Hi Talia

Your creating a great deal of suffering for yourself. As you have had affairs in the past that did not work out and that this man is married something else is going on which has nothing to do with what this guy does or doesn’t do. Getting to the bottom of that before involving yourself any more may be helpful.

I don’t mean to be cruel but you need to stop contacting married men. I don’t think  “just friends”works for you or that your ready for that.  You like the attention and validation you get from good looking guys however until you discover that such validation isn’t required for a strong sense of self your going to recreate the scenario repeatedly until you learn the lesson.

You might want to create some space, with no men, and really look at what you want for yourself and what you want from a relationship.

David Richo books on relationships might be helpful for you.