If he's asking to be "friends," perhaps you need to point out that you will be exs and you expect that being too friendly with an ex is not healthy. You need to detach and form new relationships. I don't think New Guy would appreciate it if I were too friendly with X.
Your X's comment indicates that he is not ready for this to be over, in my opinion.
X said I would always be his friend, but I realized we don't define it the same way. I don't regard myself as his friend now. I am kind to him, but I have real friends--people who support and accept me for who I am. After some of his behavior, I had to ask myself if X was a friend, then I didn't need enemies, did i?
As far as how to act in his presence....you get to a point where you don't care. Sometimes I care a little, but that's just human nature.
When you are indifferent, your R is fundamentally changed.
M: 16 years Bomb 4/07 OW 20s long gone Divorced 11/09 I remarried New Guy Cooperative r w/X regarding D