Brooke breaks up with Lucas, even though she still loves him, because she saw him 接吻 Peyton. Lucas is really hurt and can't stop thinking about Brooke.
It shows how Brooke was kinda tired of how things were turning for her and Lucas and she tells him she gotta go her own way but Lucas don't wanna give up on Brooke because he's still in 爱情 with her and he really regrets all the mistakes he made.