It is okay to hang out with your ex as long as you both are on the same page and that would be the friends only page. Meet up and just see what happens, but do make sure he knows you’re happily married and you plan to stay that way. I am friends with a few of my ex’s and they all know I am in a relationship that I plan on keeping and not screwing up. Don’t fall into the ” I remember us when … ” trap either. Sometimes you remember how it was, or you’re having so much fun with this person that you start to fantasize what it would be like to be with them. This does happen…just let it stay where it should stay…in your fantasy. Good rule of thumb when dealing with ex’s or any other friend of the opposite sex is this…” would I say or do these things with this male friend if my man was sitting right here next to me? ” If the answer is YES..then all is good, if it is no..then you’re going beyond the ” he’s only a friend ” thing with him. Hope this helps and good luck!