Matt knows Levi well, after all, he's all that he's thought about since school. But Levi's married to Paula and even though she's put on weight, Levi stubbornly claims to love her. Matt thinks nobody could love Levi as much as he does.
A choice needs to be made and Matt's reached a point where he's probably going to make it for him.
No matter what the costs or who gets hurt.