I think I am giving the impression that my marriage is not a happy one. I can assure you that I feel fulfilled by it in all other respects. We love each other very much. So Purplepeony in answer to your question, not getting oral would never become a deal breaker if my marriage in all other respects remained as good as it is now. I will add that I am working through the sex issue with the DW when I can in a sensitive way, and I appreciate the advice of all of you, which I find helpful. At the end of the day, this (or an unfulfilling sex life more generally) simply could never be worth my leaving, or being unfaithful.
What I've clearly got is a marriage that contains typical results of the no-sex-before rule. In all other respects, we knew each other very well before marriage. But, in my experience, even heavy petting only told me so much about what sex during marriage would be like. Approx 50 years ago, so I understand, sex was more furtive, for want of a better word, than it is now. Someone like myself could probably have gone through life without realising that there was anything more (although Malificence, I find you comment about how you felt at 35 interesting - I totally agree). Now - thank goodness - everything is discussed more openly. What many of the churches have done (not the C of E or the RCC, but more the newer, Americanised churches) is try to market the idea of no-sex-before-marriage by suggesting that once one is married, one can expect mind-blowing sex. It's irresponsible, and I have a very strong suspicion that there are lots of Christian married couples who are, frankly, frustrated, but who can't admit to this so as not to let the side down.
In my experience of Christians as a (Christian) teenager (I am still very devout, by the way) there were a) those who quietly ignored the rule, b) those who did everything but, ie, technical virgins, c) those with sufficiently low libidos to stick to the rule, d) those who were sufficiently scared to avoid anything to do with sex, e) those who were too unattractive and f) those who by pure chance didn't end up in bed with someone else. I was a mixture of e) and f). A previous girlfriend of mine was definately c) and d) though. She set strict physical limits early. I also remember her getting upset on another occasion when her brother jokingly commented that I probably wanted to get into her knickers. I said that was true enough, but was happy to wait. She didn't like that. I am so glad that I wan't so naive as to marry her, as I think I would have ended up in real trouble.