How to be friends with the ex?

Honestly I think it won't happen. He could have formed some very strong feelings for you after being friends for so long, going into a relationship. Allow him space to figure things out. Maybe talk to girls about going out with him. That would show that you still care about him, but don't think a romantic relationship between you and him is best.

I don't think you'll be able to go back to the relationship you had before as close friends. I'm friends with 2 of my exes, and really, is more of an acquaintance relationship. We keep in touch via emails, and once in a while, we go have lunch or dinner. More like 3 or 4 times a year. I'm sure there are exceptions, but I can't become close friends because then the bf/fiance/husband becomes suspicious, so out of respect for our own lives, we just keep in touch. Matter of fact, I'm also talk to their significant others, but I never bring up the past. So honestly, If anything, maybe you can continue a link, but is not going to be a stronger connection than what it used to be. I think is best to accept the reality and just try to be a friend, but you won't do yourself any favors by trying to be a stronger/closer friend.