Before Charlie Monohan came to the The Gates, Brett was dating Andie Bates. (Pilot) After revealing to Andie that he loved her and Andie kissing Charlie, they broke up because Andie didn't feel the same way about Brett as he did her. This causes him to agree to join Lukas Ford in running with the rest of the pack. (Breach)
During one of these instances, Lukas gets shot by a hunter which Brett than kills instantly but accidentally. He and Lexie help Lukas to Coach Ross's house for him to fix up the bullet wound, all three swearing that the hunter hadn't seen anything and that nothing happened and that they ran away from the hunter. However, Coach Ross knew that Brett was hiding something and moves the hunter's body to Franklin Park. Ross is furious with Brett for lying and putting the pack in jeopardy and boots him off the football team. Later, an angry Brett wants Lexie to run with him but she refuses, saying that no one runs without Lukas. However, Brett doesn't care, and takes off into the woods in his wolf form. (The Monster Within)
Noticing that Andie was acting strangely, he tries to confront her several times but she either walked away or was stopped by Charlie, who is also concerned about her. After getting into a large fight with Charlie, he notices a strange vein-like rash on Andie as she touched Charlie in order to keep him back. He later confronts Andie, and reveals that he knows she's been acting weird because she was different, and that reveals that he is different too - a werewolf (although he doesn't actually say he's a werewolf, only flashes his eyes gold for her). Surprised, but unafraid, Andie explains him about her mother and what she is - a Succubus. The next day at school, they are seen talking like friends - much to annoyance of Charlie. Though, Brett wishes to be more, and to his personal advantage, he tries to be something Andie wants him to be to gain her heart, which doesn't work. (Digging the Dirt)
After Lukas' father's attack, Lukas gave Brett the title of leader of the young werewolves of the pack due to Brett taking off to running by himself without Lukas. Meanwhile, Andie and he bonded a little more with the knowledge that werewolves heal faster than humans, and that Andie's abilities wouldn't hurt him for long. (Dog Eat Dog)
As the younger werewolves' leader, Brett made it so that Andie was considered part of the pack, much to the annoyance of Lexie. Despite the knowledge of knowing she wouldn't really hurt him, Andie still refuses to take him up on his offer. However, he refuses to listen to her when he sees her in the hallway looking weak and moving slow. He pulls her into an empty classroom and kisses her - giving her his energy. However, she pulls away and he recovers a few seconds later. He is in love with her therefore he would do anything for her.(Identity Crisis)
Brett is the model Gates Academy student as part of the The Gates Academy Football team. However, underneath the "perfect" exterior, Brett is struggling with controlling his "animalistic" nature. Along with that he's trying to deal with normal difficulties of adolescence - girls, parents, football, etc. But the darker side of Brett is threatening to come out causing him to become a lot more violent and have pent up energy, which causes him to agree to go running with the pack.
"She's worth the risk, I love her." - Brett