Hi everyone,
I'm very new to this, but I really need some third party advice and I thought perhaps someone here might be able to help.
My husband and I dated and lived together for 3 years before getting married and have since been married for 14 years. We have one child - 14 years old (timing is everything

).
We have had a somewhat rocky, but happy marriage, albeit not a very affectionate one. We have always loved each other deeply, but were not as attentive as we should have been as far as displaying physical affection.
This lack of affection never really bothered either of us until about 8 years ago when I began to feel very... unloved, undesired, almost abandoned. Enter, the other man... I met someone that showed more affection and openness than I could ever have dreamed. It was an emotional affair, but I felt very guilty and confused, left my husband, and began seeing this new man.
We were apart for almost a year and a half, during which he also began seeing someone. We remained friends and were always there for each other. In fact, outsiders always seemed surprised that we were seperated.
During that time, I came to realize that I'd made a terrible mistake. Somewhere along the line, I got caught up in the whole "love you but not IN love with you" bologna and became confused. I was young and I suppose I thought marriages should always be passionate. I was so confused and made a terrible mistake!
We both decided after that long year and a half to drop the outside influences and bring our family back together. We worked hard to bring some attention to each other back into the marriage and I thought we were very happy.
Then 2 years ago, I borrowed his truck to pick up his birthday present and found printouts of womens profiles from various "dating" sites. I'd never felt the need to look at his email before, but then I did.
Upon logging in I found that he'd been quite active persuing past love interests as well as new ones during his lunch hour and while he was supposedly "out with friends".
I confronted him, and he confessed to sleeping with many women during a 6 month period of time. Some that he knew locally and others that we just met online for a "one-time" whatever you want to call it. He said this was because I did not appear to desire sex anymore. We had sex on a daily basis, but he did not feel as though I desired it as much as I used to and it hurt his ego.
I explained to him that that might actually be true, but all that I was missing was a little forplay and perhaps a little "nice sex" instead of "lazy sex". I do hope I'm not going into too great of detail. I apologize if so.
Within a few hours, I agreed to forgive and forget and he agreed to work on being a little more forthcoming in the other department. I never brough it up again, never through it in his face, and worked through the pain internally. I made myself trust him when I felt betrayed and over time it began to feel more like an old nightmare than reality. Again we seemed to be happy and our sex life revived.
Then about a year ago he started spending more time "out with friends" again. I set my fears aside and assumed I was being paranoid. I did my best to support him, but he stayed out later and later and more and more often, until finally he was coming home at 6 in the morning, drunk, and claiming to have fallen asleep in the truck before leaving the bar. I brow beat him until he filing confessed that while he still loved me, he was not IN love with me anymore and felt it was too late to fix the marriage. He wanted out, but "no there is no other woman". He is just not happy and doesn't know what he wants.
I tried to offer a time apart where he could stay with a friend or something. He said that was fine but that he wanted to see other people because he "could not go withough sex that long. I had a real problem with that, but tried to embrace this and suggested that we could just date and have sex with each other from time to time. Solves the sex issue, gives us a chance to date and see each other in the way we used to, but not too damaging, or so I though.
Two days later, after more brow beating because things still didn't seem right, he announced that he was dating and old friend of mine and that there were having sex, but (as if this makes it any better) he is having a hard time "completing the transaction". I will not pretend here that I feel bad for him or her for that little tid bit.
Anyhow, for the last two months he has been pretty much coming and going as he pleases. He spends the night with her 3 or 4 nights a week. He says he is looking for another house, but he's not really making much of an effort. He spends ever last cent of his paycheck on his truck payment, gas, ciggarettes, and going out with her, while I pay the bills and he's still here. And to top it all off, he still wants to have sex with me. I am ashamed to say that I have given in to this several time, as disgusting as it makes me feel afterward, because I miss being close to him and he says this is the best sex he's ever had, but that it still won't work if he stays with me, he still wants to leave, and he's still spending half the week with her. When he's here, we get along just fine and I am doing my best to be there for him in the only way he'll let me - as best friends with some occassional sex.
Well, that's the dirty truth. I guess I'm just looking for some general advice about what I'm doing right or wrong. I am also confused about having sex with him. I don't feel like this is over, despite his statements, and without her influence I think he'd have made the decision to stay already. Should I stop having sex with him, despite my own desires? Should I force him to leave the house? If I do that before he's ready, he'll just move all the way in with her... And then what about my poor 14 year old baby. We are all so close! This will tear him apart and he has no idea any of this is going on. He just thinks dad is staying out very late for his pool league!
Thank you to all who have borne through this very long post. I'm so sorry to have gone on for so long!