Well, tough question you are asking here. I wish i have an answer for you. But i Don't. By reading the comments here, i agree with many things, most of which is the "walk away" part and "no losers but you and the wife" part, etc.....
I am currently in a similar situation, except that.......I am the wife !!!!!!!!!!! Yes !!!! the one who has been cheated on. Forgive me here, but for me she is nothing but a bitch, and a home wrecker, not that he is not to be blamed here, but she could have stopped him, or "walked away" !!!!!! Most men search for new stuff, new excitment in their lives, specially if they have been married for almost 5 years now !!!!!!!!
I am feeling so bitter right now, my life is ruined, and i am hurt, betrayed, and vengeful...........
You would better walk away, and not ruin someone else's life .....