What you describe is actually common for men of sexual abuse. It's because we sometimes have difficulty differentiating sexuality, love, nurturance, affection and abuse in relationships that involve intimacy, sexuality, and/or love. It affects us in such a way that we even question ourselves when we are being sexual (like in the case you described with your wife). Ambivalence about sexuality in general is also common. We survey our own sexual feelings (like the way you describe) as well as from others.
In my own case, I was so ambivalent about my sexuality I didn't lose it until I turned 27 (which I got a lotta flak about
. After having questions about it for years (will the person mind if I do this, how will she see me if I do that, will I get an erection if she wants to be intimate) I dove head first into sex with another man and the whole experience was vague for me. On top of that, I didn't get the climax that I thought would answer questions about my own sexuality. Also, I didn't even want a friendship with the guy afterwards. Women? Even though I was abused by one, I was wary of them, yet I love flirting with them. I love the emotional connection I get with women, but sex? I dodge it like a bullet because not only am I afraid of doing the things I want to do (lest she think I'm some sort of pervert) but also because I feel as if sex will make the relationship rotten AND because I'm afraid I may not enjoy it.
I really wish I could help you more, but then I think about that>