"Your rectum or mouth is not made for sexual intercourse"
Indeed they are not and whilst I have no desire to use anyone's rectum for sexual intercourse I think that oral sex is a thoroughly enjoyable sexual practice, you might be more uptight about such issues and that's fine, that's up to you, but please don't feel the need to judge the rest of us more rational people on the basis of your own particular hang-ups.
Well, you know what happens when you ass-u-me.
You might want to exam your preposition since someone who simply points out a medical fact is now a accused of being uptight, judgmental and an irrational prude.
Personally, the marriage bed between a man and women is made for pleasure whatever form that might take.