What would you do if you were me?

I've been married for few years. However, my husband mentally cheated on me last year with a co-worker online (she worked oversea). Things were bad for awhile, for my son, I faught to keep our marriage. Things are back to normal. However, I can't trust my husband nor should I trust him. I found him search his ex-wife on the internal also looked up escort service on Craiglist. There's another guy who I never dated but we did just about everything a bf/gf would do in college except holding hands/kissing/sex. He's a total gentleman and almost everything I wanted. I let the chance slipped away. Now 10+ years later, I found that I still have the same feeling toward him, if not stronger. He's never married nor have a girlfriend. I believe he also has some feeling remain for me. But I don't know what to do. I don't know if I should live in the pretend happiness so my son would have a perfect family when he grows up or should I go with my guts and gamble to see if the college sweetheart really is what I wanted. What should I do?