"All At Once" by the Fray
Kind of AU (involves BL and JP).
Lucas and Peyton used to be in a relationship but they ended it when she had to move away. 2 years later, she comes back to Tree Hill unexpectedly much to Lucas's surprise who is now dating Brooke. Thinking that he has moved on, Peyton decides to give it a go with Jake. Lucas sees them together and realizes that he isn't over her so he goes to confront Peyton which ends in a fight but they both realize that they're still in love with each other. Meanwhile both their relationships are falling apart until finally they decide to do what feels right and end things with Brooke and Jake and be together.
simply infatuated net/simply-infatuated/thefansite