The fact that your H knew about your preferences before marriage and decided to marry you anyway disturbs me. If his needs for certain sexual activities was so strong, he shouldn't have married you. He was dishonest with himself and you when he married you. Now that he's got you committed, he's playing hardball by bringing the OW into the picture. Like, do what I want or else I'll find someone who will do it. Sorry, he knew what he was getting. Deal with it!
It would be no different if the both of you decided not to have children (or alternatively that you did want children), then the other person changed their mind. Because he knew about your preferences in advance, he has no right to insist you perform, IMO. Asking you to change yourself to suit him now, after the fact, is unfair to you. It is ok to ask, of course, but since he knew the goods he was getting when he got married, his choices now are a double betrayal. You were honest with him, and now he is bailing on his promise. He is the one who needs to deal, not you.
The suggestions of the people here that you come up with some kind of mental rationalization to "overcome" your beliefs in order to meet your H's new needs is disrespectful. Just because lots of other people "do" certain things doesn't mean you have to. Like I said, you were up front with your H before you got married. If he decides now that he is going to change the rules after the fact, it is his problem. His "needs" do not outweigh yours, and you should not be asked to compromise something you were upfront about since the beginning of your relationship.
If he wants to find someone who does X or Y or Z in bed, fine. He'll figure out (eventually) that it is much, much harder to find someone who will do A-W with the other 23 hours of the day.
Isit2late said: "Now you have a choice to make. You can continue in this belief that there are just certain things that you will not do, or you can decide that cherishing, redeeming, and celebrating your marriage are important enough for you to question long-held beliefs."
Hmm, since when does cherishing and celebrating your marriage have to do with letting someone else's sexual practices overwhelm your beliefs? Her H is the one who has not cherished his marriage. What you are saying is that her sticking to her original agreement is somehow a failure on her part to cherish her marriage. Bull. Sounds like her H, in his quest for the perfect b**wjob, or whatever, has decided to throw out his commitment. Simple as that. Also, couching certain sexual practices as an emotional need gives people like him the justification to go out and do exactly what he is doing too. Getting a b**wjob, or whatever, is not an emotional need.
Anyway, he knew what the rules were before he got married. It is just too bad for him if he decided he doesn't want to follow them anymore. I'm sad for you, Ravenhair, that your H has decided not to stick to your original agreement. In the long run, though, I'm sure you will feel better about yourself if you don't let your H bully you, coerce, or intimidate you with the idea of a OW in order to get you to change your beliefs.