A lot of folks on this board seem to be of the opinion that if a man doesn't want to have sex he is gay, depressed, having an affair, out of love, suffering from a medical problem, etc etc. I'd like to offer another perspective on all this. I have been married to a beautiful woman for ten years who is smart and outgoing and has always been my best friend. We communicate well, we have the same values, we have the same sense of humour. In every possible way, we're great together except ours is (by Dr. P.'s definition) a sexless marriage.  
 
It's not her, it's me. And it's not that I am not interested in sex, because I am. I'm not gay, have been checked medically and wasn't having a relationship outside the marriage and am a very healthy, successful guy in his late 30s. I'm good around the house (I'm responsible for vaccuming, dishes and the outside of the house, she's got laundry, the bathrooms and cooking and we split parenting duties right down the middle, too). I have nothing to complain about and, on the outside, neither did she -- except that nothing was happening in the bedroom.  
 
What WAS happening was that every time we got into a fight (which was often in our early years though much less so now) I pulled away physically. Even though things eventually became really good between us, I just got into the habit of withholding whenever we argued at all or when I felt underappreciated. I knew she wanted sex just a little more than I did, so I used it as a weapon. It's a passive-aggressive response, I realize now and the healthy thing would have been to seek counselling early on, but no man I know readily wants to admit to not wanting sex (probably because if you don't, people label you gay, impotent, etc. etc. as folks are doing above ). I simply didn't understand what I was doing or why and, the more we talked about it, the worse it got (probably because I saw the discussion as a form of "nagging" ... if you can believe it).  
 
So here's the dynamic: as good as my wife is, she's not perfect and she can "nag" about stuff which, in turn, makes me less likely to want to be with her which makes her anxious and - you guessed it - more prone to complain about little things. It's a downward spiral.  
 
Let's do away with the easy stereotypes, folks. For men -- as well as women -- the most important sexual organ is the brain. And guys often need just as much validation and attention from their mates to feel sexual as women do. This stereotype about all men being sex-driven beasts may be true for many men, but it's not true for all of us. We're not above being just as passive-aggressive as some women can be -- we're just less likely to understand it because we're generally less self-aware.