Wow- sorry,I didn't know that you two were together for so long! If there weren't children involved, then I'd still advise you to leave him. Even tho he swore he'd never be like his step-dad & cheat, that man was his male role model & he is already kind of cheating-he's trying to hook up with other women by sending them sex emails. I guess the only suggestion I can give you would be to go to couples counseling. Hold off on the wedding until you are sure that you'd be making the right decision. If he's only been with you (or had very few partners), maybe he's curious about other women now. Or maybe there are other things going on in your relationship that are bothering him, & this is how he's expressing it. Sorry you're going thru this.