I wonder how much of this is fear of female sexuality? I am not familiar with any biblical or church teachings about particular sex acts - I think I fantasized my way through that portion of the teachings. But here is where it gets interesting to me.
Female sexual pleasure is so feared, that the "liberal" Hollywood ratings systems, will give an R or even PG13 rating to a film which depicts the torture, stalking, murder, sexual degradation, and gang rape of a woman, but will slap an NC17 (the kiss of death at the box office) to any film depicting a man going down on a woman and focusing on her pleasure.
Now this is interesting, because for a short period, in the 70's, it was not like this. Very few scenes more erotic than Jon Voight going down on Jane Fonda in "Coming Home" have been shot in the mainstream. The scene almost completely focuses on her pleasure, and on her face as she gets lost in erotic pleasure, and makes it apparent that this is a somewhat new and revelatory experience for her.
Flash forward to today. In the film "Blue Valentine" Ryan Gosling performs oral sex on Michelle Williams. It's a decent scene but nowhere near as erotic as the Voight/Fonda one. Well, this caused a ratings board meltdown. A woman having an orgasm! Sure, it's okay to depict a terrified woman being brutally raped, but this! My god think of the children! They slapped it with an NC17 rating. The stars had to fight to get an R. Gosling himself came out with a statement accusing the entire system of being misogynistic (he was right). Eventually, the ratings board folded.
Considering how patriarchal religion is, I wonder how much of this is mixed up in this nonsense.