Thanks for all your inputs.  This really helps me take a step aside and not get so caught up in him.  I am definitely going to go for the respectful geeky, nerd next time if I ever leave this marriage.

My ex cheated more than I want to know. He is off having the good life in Texas trying to immigrate the new wife into the states. Because I handled all the finances he felt entitled to cheat. I had the money, he was taking care of me. He hid what he was doing very well. Home every night right on time. Never went out with his co-workers.
 
By the time you figure out what is going on you feel caught in a marriage you thought would last forever. It's not that I don't respect myself. He didn't respect our marriage vows or anything else. He brought many other women into a relationship meant for two. Then he married someone else while still married to me. I opted to get out while I could. He threw away a 33 year marriage for someone who was 35 years old.  I feel a great deal of pity for him because I now know what he is.
You've already said it's a vicious cycle. Only you can decide how long you want to continue in that cycle. Because it will continue.
I agree with what georgann, wow and Mechele had to say.
I wish you well whatever decision you make.

Oh I went through that vicious cycle over and over again, because I loved him so very dearly. I discovered his cheating, left and stayed away nearly a year, went back to him to "try" it again, and after being with him a few more years and discovering even more other women and hidden money, I tried to work it out with him, but it was one-sided. I couldn't stay because the trust was just gone. I went through YEARS like this and I wished that I had done something about it sooner than I did, but I had so much love for him and convinced myself to stay.  I have learned that only you are the one who can make that decision about leaving but it has to come when you are truly ready.  Best of luck to you.

Nascar,

I don't know if you have had a chance to read my journal, but my situation is very much the same as yours.  I recently found out my husband was having yet ANOTHER affair.  I don't trust him as far as I could throw him.  I too, still love him very much.  But a marriage was built for two and not three.  I definitely believe the situation is abusive and manipulative.  I think they are so comfortable in the living arrangement that they think they can manipulate you in to accepting just about anything under the guise of "I love you".  It is very hard for me to let go because I do love him, but I need to love myself more.  Georgann is right about respecting yourself.  But when you are in our situations, you lose respect for yourself basically without even realizing it.

Me too! Past girlfriend and match.com.  He has every exuse in the book.  The problem is he does it nicely and leads me to believe we have hope and on those topics he says I made bad decisions when I was upset but did nothing. I even spoke to the ex and she said nothing happened.  Do I believe that?   I feel your pain, do I throw away 10 years or find away to believe him

It comes down to respect for yourself.  It seems he doesn't have any respect for you since he is doing this all behind your back.  A marriage is based on trust, respect and friendship, as well as love.  It is hard to keep that combination all together.  You deserve to be treated well and with respect, not betrayed.