I'm having the same problem now with my fiance but in reverse. Our relationship has always been quite open - we've frequently done mutual masturbation, etc but due to hard work and stress and my medications, my sex drive has dropped from high to almost zero. The problem is that I wouldn't mind continuing more of that now, except for the fact that he pouts when I tell him that I'm just not in the mood. And I'm not. Like, really, really not. His pouting makes me feel like I'm obligated to have sex with him (he complains if it's been more than a few days) and I feel like I get hounded for sex (a common phrase around here is "aw, why not?). This is building up resentment very, very quickly. He knows I'm on medication, we've had numerous discussions about how my sex drive is much lower than it used to be and I've also discussed with him how I really don't appreciate getting pushed into it. It doesn't help. It's like it goes in one ear and out the other. I still want sexual contact from time to time, but he thinks that means that I obviously want sex - so I'm getting more and more hesitant to even act like I have a sex drive at all around him because any resistance on my part will get me an earful of whining on his.

I guess where I'm trying to go with this is that maybe your husband feels pressured by you to do something that he may not always be in the mood for and it's just easier for him to please himself when he feels like it rather than deal with the whole boatload of issues that comes up between you two at the mention of sex.

some of it's magic
some of it's tragic
but i had a good life all the way......
~jimmy buffett