Their romance slowly developed throughout season 1A. Brandon soon confessed his feelings for her early on in the series, in The Morning After, but she rejected him due to a bad experience when she was raped by a former foster brother, Liam Olmstead. Also because of the experience, she knew getting involved could mean she and Jude being kicked out of the house. Instead of dating Brandon, she began dating Wyatt. When she and Wyatt had troubles, she turned to Brandon as a friend. When Stef is at the hospital after being shot, Callie and Brandon share a moment when she talks about her deceased mother to him. He comforts her and the two are on the verge of sharing a kiss. This, all the while, is being watched by Wyatt from a nearby window. At the hospital, Wyatt encourages her to go after Brandon, but she is halted when Talya shows up. During Stef and Lena's wedding preparations, Callie brings Brandon to an alley. She confesses that she knows what she wants now before she kisses him; they make out until Jude furiously interrupts.
In Season 1, they became an official couple despite the various roadblocks. He snuck out to meet her at Girls United, and they saw each other at a museum. They texted during Callie's temporary move. They were once thought to be broken up due to a misleading text sent by another house member. When Stef's father dies, Brandon is tempted to tell everybody that they're dating, but Callie is not ready. After a tough time, they agree to a mutual break up yet also confirm they do love each other - but Callie needs a family more than a romance. The relationship struggles when they both have a tough time getting over each other, though Callie gets back together with Wyatt. Brandon is left on a thread after taking the blame for alcohol brought to a school party which was pinned on Callie and when she lies to him about sleeping with Wyatt. As Brandon gets into the cop car, Callie confesses to Brandon about lying when she said she slept with Wyatt.
In Season 2, their relationship becomes platonic while also developing more in a sibling manner of affection. When Lena is at the hospital, Brandon tells her that he knows what it's like to love her and not knowing why she shuts people out. She also admits to Daphne that she may still be in love with Brandon. At a Mexican street festival, Liam returns, and Wyatt feels threatened what he may do since Callie is there as well. Wyatt confronts him, only to punch Liam in the face. Liam retaliates. Brandon notices the fight and tries to break it apart. Liam strikes at him with his elbow, and Brandon joins the fight. Meanwhile, Callie notices this but doesn't know how to feel with Brandon. After the fundraiser to get Girls United a new home, Brandon notices Callie running away from the party and goes after her. He asks her about it and tries to reassure her that the Quinn's can't make her stay with them. Callie, knowing that she may never be adopted after Sophia and Robert's betrayals, thinks that the adoption is the way it's supposed. She tells them that she gave up so much to get adopted, and they kiss. After Brandon takes time to think about them being together, he decides that she shouldn't give up on getting adopted, because she doesn't commit to what she wants, and he doesn't want to be her backup plan and goes back to Lou.
In Season 3, the social worker who is supposed to recommend Callie for adoption finds the restraining order took out against Brandon and must investigate Brandon and Callie's past relationship. At Girls United, Rita is accused of hitting Carmen which Carmen corroborates under blackmail from another girl named Brooke who'd actually hit the latter. Carmen admits the truth to Callie with Callie recording everything to prove Rita's innocence but then Carmen threatens to tell the social worker about Callie's relationship with Brandon when Callie was at Girls United. Callie sends the recording anyway to save Rita's career. Believing she won't be adopted, Callie and Brandon have sex at Idyllwild. They later exchanged "I love you"s and plan to tell their moms about their relationship, but when Rita surprisingly convinces Carmen to keep her mouth shut, ensuring Callie's adoption goes through as planned. After a difficult time on deciding what to do, they break up again in order for Callie to finally get adopted and agree to keep quiet about their night together.
In Pilot, Brandon and Callie are first introduced to each other at the dinner table. He Brandon helped Callie with navigating through school and the Foster family. Callie uses Brandon's phone to contact her brother, Jude. Callie joins Brandon in the music room. He explains to her about the twins moving in. After Brandon sees Callie throwing her agenda away and wandering off, he blows his girlfriend, Talya, off and chases Callie. When he finally reaches her, she tells him that she has to get her brother. Brandon seems conflicted on whether to skip class or follow Callie. He ultimately decides to follow her. On their way to her former foster father on the bus, Callie explains to Brandon why she ended up in a juvenile delinquency which leads her to plan on rescuing Jude. At their arrival, they come up with a plan that includes Brandon to distract the man while Callie gets Jude. Callie goes through the back door while Brandon is talking to the man. The man sees Callie and starts yelling at her. The man pulls out a gun and holds it at Brandon. They are later safe. In the car, Brandon and Callie are seen looking at each other for a short moment.
In Consequently, Brandon lets Callie stay with him in the music class during lunch. They joke around and Callie plays the guitar. Callie says that her mom taught her to play it before she passed away and Brandon rubs her knee in comfort. While walking home from school, Jesus brings up Callie. Both Brandon and Jesus think Callie is hot. Back in the backyard, Brandon helps Callie with her guitar abilities. At night, Brandon and Callie are in Brandon's room making music. At some point, he receives a text message from Talya asking when he would come over. He blows her off again to stay with Callie resuming making music and enjoying each other's company.
In Hostile Acts, Callie meets up with Brandon. She tells him that she knows that he's planning on moving with his father. She asks him if it's because of her and Jude that he is moving to which he answers no. When Brandon leaves to move in with his father, Callie gives back his guitar. He insists that she keeps it.
In Quinceañera, Mariana asks Callie to be in her court. Callie agrees. It is revealed that Callie would have to dance with Brandon. Callie seems uncomfortable with Brandon and Talya ergo she leaves. Stef thinks that there's something going on between Brandon and Callie and warns him that it is against the rules to hook up. Brandon thinks otherwise saying that there is nothing going on. During practice for the Waltz, they share intimates moments. When Callie steps in the dining room in her pink dress, Brandon turns around and can't help but gaze at her. He tells her that she looks "nice" while Talya walks in. Talya threatens Callie. As they are about to do the entrance, Callie switches partner with Sam. During the father-daughter dance, Brandon asks Callie what happened. She tells him that Talya thinks Callie has feelings for Brandon. Brandon looks at Talya in disgust. After the dance, Brandon tells Callie that she's dancing with him. Callie attempts apologize to Brandon for what she said about Talya but he disregards it. After the dance, Brandon and Callie are still dancing with each other. Talya interferes but Callie leaves. Brandon looks sad when she does so. Brandon grabs Talya's hand and drags her away. After some time, they argue. They eventually break up. During the photo session, Callie asks Brandon about Talya and he says that she left. Afterward, Brandon tells her that he broke up with Talya. Callie assumes that was because of her to which he says no. He broke up with her because she's doing stupid things like reading Callie's journal. Callie assumes that Talya told him about the journal and he says that he didn't want to know because he knows everything he needs know about Callie. They stare at each other but Callie runs away. Brandon tries to stop her but fails. As Brandon walks with Mike, he sees Callie's shoes on the stairs like in Cinderella.
In The Morning After, Wyatt comes to the barbeque. Brandon looks annoyed and Callie tells him that she invited him. Brandon becomes jealous enough to warn Callie about what Wyatt could do and he explains that Wyatt and Talya used to date. After Wyatt and Callie get caught at someone's else house and have no other way out, she calls Brandon for a ride. When they arrive at home, Brandon is angry at Callie. They get into a small argument. Brandon confesses his feelings for Callie saying "I don't want you dating Wyatt because I don't want you dating anyone [but me]". They stare at each other for a while. Callie answers that she can't date him. Callie argues that a former foster brother got close to her but said to his parents that Callie came on to him (maybe Liam) but Brandon insists saying "Well, I'm not like him. I would never do that." Callie leaves out of his gaze and Brandon looks hurt.
In The Fallout, after Brandon prevents a fight between Wyatt and Liam to worsen, he and Callie walk home instead. Callie confides him in some information about Liam to which he answers that it's not cool. In the morning, Brandon proposes that she tells Bill about to which she rejects. Brandon helps Callie with Sarah. Callie confides in Brandon into explaining Liam and the night she got raped. Brandon feels sorry. Callie allows Brandon to stay with her while she explains everything about Liam to Stef and Lena.
In Clean, Wyatt becomes jealous of Brandon and Callie's relationship to which she denies. Brandon asks why would Talya think that Brandon and Callie are together now when she isn't with Wyatt and she disregards the question.In Vigil, Callie asks Brandon if he and Talya are back on. Brandon answers that he doesn't know and Callie looks hurt. Callie helps Brandon with his relationship with his foster siblings. Brandon and Callie have a moment after she explains to him about her deceased mother as Wyatt comes in. Wyatt tells Callie that he knows that she likes Brandon. He encourages her to be true to her heart and seize the love she feels for Brandon as life is short and she may never have the chance for it again, using Stef as an example. Callie kisses Wyatt on the cheek, leaves him and rushes back inside to tell Brandon how she feels. However, as she is getting close to Brandon, Tayla runs up to him and the two embrace. Callie quickly makes a turn away into the waiting room leaving her hurt.
In I Do, Brandon encourages Callie to pursue Liam into court. In Mariana's and Callie's room, Callie yells at Brandon saying that her life will never be okay due to her past. Callie and Jude receive news that they are getting adopted by Stef and Lena. Brandon says that there's enough to go around. Before the wedding, Callie asks Brandon to talk. She leads him to another area. She thanks him for believing in her when she didn't believe in herself and she tells him that she knows what she deserves now. Brandon answers saying that she deserves to be happy (to which he may imply to be with him or to be happy in general). Brandon compliments her and repeats that she deserves to be happy and everything she wants. When Brandon asks for her opinion, she kisses him taking Brandon by surprise. The kiss deepens by the second. They are interrupted by Jude and results in Callie running after him. Talya unknowingly shows up and takes a reluctant Brandon away. Callie apologizes to Jude for being selfish (from the conversation they had) and promises she will not do so anymore. After the wedding, Callie packs her stuff and leaves. The reason why she left was due to promising Jude she wouldn't be selfish meaning that she wouldn't involve herself with Brandon anymore which is a promise she knows she can't keep. Before leaving, she says her final silent goodbyes to Jude and Brandon respectively. She runs away with Wyatt to Indiana.
In The Honeymoon, Brandon and Jude get into argument about his relationship with Callie. When Jude tells him that he not any better than Liam, Brandon defends himself by saying that he isn't Liam and he loves Callie.In House and Home, Brandon gets annoyed when his family assumes that Callie ran away for no reason. He tells them, during dinner, that she left because he kissed her. Everybody tries to convince him that this phase will pass. He ignores them throughout the episode. Brandon searches for Callie's group home on his laptop. Later on, he overhears his mother talking with Jude and Mariana about visitations. Brandon is supposedly at piano lessons started by Lena. After Cole and Rita leave Callie alone, Callie notices Brandon across the street from her group home. She runs outside, and they embrace since she ran away.
In Things Unsaid,
In Family Day,
In Adoption Day,
In Things Unknown, Brandon and Callie talk after all that has happened in the Season one finale. Callie tells him she doesn't want to look for her biological father, as she will be 18 soon. She hints at possibly wanting to reconcile her relationship with Brandon at that time, saying they won't need anyone's permission.
In Take Me Out,
In Truth Be Told,
In Leaky Faucets,
In Christmas Past,
In Over Under,
In Mother Nature,
In Déjà Vu,
In Going South,
In It's My Party,
In Mixed Messages,
In The Show,
In Kingdom Come,
- Brandon helps Callie's transition into the Foster family and into school.
- Brandon ditches his girlfriend, Talya, to chase after Callie.
- Brandon joins Callie to find Jude.
- Brandon was the only one Callie told about her foster father and the abusive past.
- Brandon distracted Callie's former foster father so Callie could get inside the house.
- Brandon almost got shot by her former foster father for Callie.
- Brandon gives Callie his old guitar.
- Callie tells Brandon what happened to her mother.
- They play music together in the music room at school.
- Brandon rubs Callie's knee, comforting her about her mother.
- Brandon stays home, and plays music with Callie, instead of sneaking out and being with Talya.
- Callie asks Brandon if he's moving in with Mike is because of her and Jude.
- Callie asks him "Then why are you leaving?" after he responds that he's not moving out because of them.
- Callie tells Talya that he's probably not moving out anymore.
- Callie tries to give Brandon his guitar back.
- Brandon refuses to have it back, by saying to "keep playing it."
- Brandon is Callie's waltz partner.
- Brandon was speechless when he sees Callie in her dress.
- Brandon gazes at Callie, telling her that she looked nice while stuttering.
- Brandon dances the waltz with Callie, even after Callie reveals what Talya said to her.
- Brandon breaks up with Talya and defends Callie.
- Brandon tells Callie he broke up with Talya.
- Brandon yells for Callie when she runs away from him.
- Brandon looks for Callie.
- Brandon realizes his feelings for Callie in this episode.
- Brandon is jealous of Callie and Wyatt and asks why he is at the family barbeque.
- He tries to convince Callie that Wyatt is only trouble.
- He is annoyed when Callie asks if he could pick Wyatt and her up.
- Later, he tells her, "I don't want you dating Wyatt because I don't want you dating anyone.", implying that he wants her to date him.
- When Callie says that she and he cannot date, he insists.
- After Callie tells him that she was taken out of a foster home because she was friends with a foster sibling and that he lied and said that she was coming onto him, he says that he would never do anything like that.
- He's hurt when she tells him that it would all end the same, with Callie and Jude being taken away.
- Seeing Callie and Wyatt in the hallway, he glares at them and walks away when they kiss.
- Brandon and Callie were arguing in the morning at breakfast.
- Brandon and Callie are seen at school during the fight between Liam and Wyatt.
- Brandon and Callie walked home together from school.
- Callie told Brandon what happened between her and Liam.
- Brandon helped Callie with Sarah.
- Callie confides in him about the night she got raped by Liam.
- Callie asked Brandon to stay when she told Stef and Lena about Liam.
- Brandon and Callie are seen at dinner at the beginning of the episode.
- Brandon and Callie are seen in Algebra when Talya got humiliated.
- Brandon and Callie are seen talking about Talya's drunken actions.
- Callie dodges Brandon's question that why would Talya think if she and Brandon are together if she isn't with Wyatt.
- Brandon and Callie are seen talking at the home about how he doesn't know what it feels like to not have enough or to not be wanted.
- Callie opens up to Brandon about her parents.
- Callie and Brandon were looked like they were about to kiss but were interrupted by Wyatt knocking on the door.
- Callie reveals her feelings in this episode about Brandon.
- Callie was about to tell her feelings to Brandon until she saw Talya come.
- Callie finally tells Brandon her feelings for him.
- Callie thanks Brandon for believing in her.
- Brandon compliments Callie by calling her amazing, kind, smart, and beautiful.
- Brandon tells Callie deserves to be happy and have everything she wants.
- Callie kisses Brandon and seems to be happy about it.
- Brandon and Callie make out but they get caught by Jude.
- Callie visits Brandon last before she runs away.
- Brandon tells Jude he is not Liam and that he loves Callie.
- Brandon was very upset when Callie ran away.
- He asked if Wyatt and Callie are still together.
- Brandon, once again, says that he is not Liam and that he loves Callie.
- Brandon visits Callie even though she lost her privileges.
- Brandon and Callie hug on visitors day.
- They share an embracing hug.
- Brandon gets a restraining order to prevent him from seeing Callie
- Callie uses the emergency phone to tell Brandon about the field trip
- Callie goes on a field trip with G.U.
- Brandon goes to see her on the field trip
- Brandon and Callie kiss
- Brandon tells Callie to get emancipated so that they can be together
- Callie thinks about applying for I.L.P.
- Brandon stops taking piano lessons so that he can help Callie with Independent Living Program
- Brandon thinks Callie is breaking up with him
- Callie realizes that Cole sent those texts to Brandon
- While Callie is helping Daphne with her apartment Brandon comes to see Callie
- Brandon and Callie kiss
- Brandon talks with Callie when she is looking at the wedding picture.
- Brandon places his hand on her back while he is taking her to his room
- Brandon wants to tell Stef and Lena about his and Callie's relationship.
- Brandon is concerned when Callie is forcibly caressing her neck looking for her necklace
- Brandon felt bad when Callie was crying
- Brandon finds Callie's necklace.
- Callie states Brandon as “ My Hero “
- They share their “ I love you's “ and hug
- Brandon comforts Callie after she reveals to him that she can no longer get adopted.
- Brandon and Callie kiss.
- Brandon performs a piano piece he wrote for Callie, making eye contact throughout the song.
- They talk and Brandon says he doesn't care about himself but cares about Callie.
- They stare at each other until Brandon calls it a night.
- They look at their bedroom doors, thinking of each other.
- Brandon and Callie have sex.
- In I Do, Callie and Brandon made out for 34 seconds.
- They both like to play music. Brandon plays the piano and guitar. Callie plays the guitar, they are also known to be very good singers as well.
- Brandon was the first to have feelings for Callie.
- Brandon says in 1x20 that their love is a once in a lifetime thing.
- They have sex for the first time in Idyllwild (3x09).
- They have shared six on-screen kisses.
- In Padre, they break up because Callie claims 'she needs a family more than she needs a boyfriend.'
- Callie tearfully reveals to Stef and Lena in Kingdom Come that her sleeping with Brandon is not just a rumor and that they did sleep together, much to their shock.
- Kissed: I Do (1x10)
- First Relationship:
- Kissed: Someone's Little Sister (2x10)
- Second Relationship:
- Start Up: Idyllwild (3x09)
- Broke Up: Lucky (3x10)
- Reason: Once again they realized Callie needed a family more than their relationship.