He loved her but they could never be together there was someone else. He admired her most of all respected her even though she ended up with the wrong guy. She was getting played cheated on but fighting to make it work.
Once she got in a relationship, she gave up on their friendship.
He was there through the tough times he'd learn that his chapter was over in his life forgotten left in the past. They'd cross paths from friends to complete strangers. Both doing their own thing the future divided them. Desired different things instead of each other.