Personally, I don't think that you should contact a married man regarding a previous or potential relationship with him.
As for the friend, it's not his business, so I wouldn't contact him, either.
If you got in touch, what might it do?
If he decided that he wanted you again, & got back with you, his wife could blame you for wrecking the marriage.
If he
did get back with you, it could all start again, anyway. He could decide that he had made another mistake, it's his wife who he really wants, after all. (The grass is always greener on the other side.)
What if this friend has got things wrong or is just trying to stir things up and you were to contact your ex and it caused upset for all of you ~ and you were blamed. He might become really annoyed with you and his wife might think that you were trying to wreck their marriage in a fit of jealousy.
Only you can decide what is the best thing to do, but sometimes, if memories in the heart over-rule common sense in the mind, people can make big mistakes. Please make sure that you don't.
Having said all that, maybe this chap really does think that he has made a mistake and really does think about you ~ and maybe you
are simply meant to be together. However, if this is truly the case, you should only get involved with him, again, if and when he and his wife have decided that their marriage is over.
Even then it may be that he is a dreamer who cannot commit and it might not be good for you.
You are very young. Time is on your side. Give yourself a chance to enjoy yourself and find someone who can make you really happy. You cannot follow this up now, anyway.
Good luck
