You should leave this man immediately.
He does NOT love you and will NOT leave his wife for you. THis has been going on for two years, and it still isn't plain as day to you?
Don't make excuses for him and say "he doesn't really love his wife" or "unhappy marraige" This is ALL that men like this ever say, and for some reason, You fall for it! He has NO backbone. If he is having problems with the relationship then HE needs to grow a pair and work to fix it.
Instead he's getting his jollies rocked from an easily convinced and easily manipulated woman. Why work on a commitment he has made FOR life (because that is what marriage is supposed to be), when he can take the easy route and go find another woman to put his hands all over? You're the easy route, his reason for not doing the right thing. He's having his cake and eating it too, and you're enabling it. You need to have enough moral integrity to see what's right in front of you: he is MARRIED bottom line, this is NOT right under any circumstances..
Put yourself in his wife's shoes for a minuet, REALLY do it. If he was your husband, and you found out that he had been cheating on you with her for two years while you were married, wouldn't you feel absolutely disgusted? Not to mention hurt, and confused and angry and sick and USED.
And on the Off-chance that he does end up with you, who's to say he won't do his to you? He's getting away with it now, why not do it again? It's too easy.
I guarantee that he doesn't care about you the way you think you care about him. If he really wanted to be with you, he wouldn't put it off for two years.
He is with a wife. He's not going to give up that kind of security for you. You're his little plaything.
Have you ever heard the saying "guys will stell you anything" Well he's doing it, he's saying whatever he needs to to keep you around so that he can keep using you..
If I have left anything out, someone, please add it.