The thought of doing something that most guys are raised not to do these days can't be easy to get past...
and sex is sex, Clinton had that point proven in a court of law. If you're going down on him and he you, it is sex, period. Your family sounds like they've tried to instill alot of good morals in you, but you're grown now, and you've made the choice to have sex. Welcome to the real world.
If you get pregnant, it's absolute proof that you DID have sex out of wedlock....and that is what your family is afraid of. Guess what, darlin, you've already done it. This was YOUR decision to make, and not theirs anyway. Go on and use protection, and stop sidestepping the issue. As mean as it may sound, these are all excuses for you to keep from having to admit (to someone face to face) that you've got a kinky appetite.
If you want to be dominated, say so, and be an adult. If you can't do that....then you should wait a while before you submit.
Are you living at home with your parents?