As the subject says, I have some theory bouncing around in my head, so I'd like to bounce it off people here. I could group the reasons I can find enjoyment from sexual activity into three categories: First, and most obvious, would be that it physically feels good. Second, in my context as a married monogamous man, being a recipient of sexual activity with my wife makes me feel good because she has an interest in providing me with sexual pleasure. Third, in my role as a giver of sexual activity I find enjoyment from the fact that I am sufficiently capable of providing for my wife an enjoyable sexual experience. Having pondered this some, I think that all reasons for enjoying sex fall into one of these categories. Any particular sexual activity that I enjoy provides enjoyment to me in one or more of these activities. For example: Masturbation obviously provides physical enjoyment, but I use video stimulation that in my imagination provides some of the other types. Giving my wife oral sex is something she enjoys very much. While it doesn't really give me physical stimulation of any of my own erogenous zones, I find it enjoyable because I get a sense of satisfaction from pleasing my wife. I find that many of the sexual activities I crave from my wife, such as HJ's and BJ's, and sex with her on top... These all have in common the fact that she is stroking my cock, and aside from the obvious physical sensation benefits - these things provide me a sense that my wife has a desire to provide me with sexual enjoyment. I think this has some use. For example, it provides a framework for understanding how the wife making herself sexually available but not being in the mood and wanting it overworth - isn't much more satisfying than masturbation. A big key to maintaining a good sex life over many years involves the basics of attraction. Just the feeling of sex without a sense of desire or worth... It's a formula you can get with masturbation, so really - speaking strictly from a standpoint of efforrt vs reward, if that was what a long term relationship was providing (sexually) then why go to that effort. Desire does have a lot of basis in physical appearance, but it has it's components that come from behaviour as well... One of those components would be that neediness is the opposite of attractive. The opposite of neediness is outcome independence. I was having a declining sex life, and certainly I had gotten into a vicious circle of wanting more sex, behaving needier, and thus getting even less sex. Knowing what I've hypothesized above, suppose I get my wife to agree to have sex when she's not in the mood. It's not going to be much more fulfilling than masturbation. So, armed with that knowledge, I find it easier to be independent of whether she goes along with an offer of sex from me - she says no, it's all the same to me, I'll take care of my need on my own. Another tricky thing for me has been explaining to my wife the things from which I find the most satisfaction sexually.. It is a touchy subject because she can take things personally, so I risk pushing her away if I express my preferences - and my preferences aren't going to be met if I don't express them. How does this matter in a bottom line kind of sense? Well, I think I've managed a lot of growth in the process of making a marriage that was on a path to seperation into a strong marriage. But I think the growth has been a bit one sided, and I need to be able to explain to my wife in a manner that she can understand without getting defensive and grow with me.