Jewish Sexuality dot Com

Question:

What advice do you have regarding proper sexual relations for a Noachide gentile? Also, I read on your website that a Jewish man is forbidden to look at, or kiss, his wife's sexual organ.  Since it is incumbent upon a husband to sexually please his wife (which I understand to mean to give her an orgasm), giving oral sex to ones wife could bring her the pleasure that is her right under a marriage contract. If it doesn't lead to the spilling of semen during foreplay, why this is problematic?

Answer:

One of the Noachide commandments incumbent upon non-Jews is the general prohibition against sexual transgression. The Zohar makes clear that rampant sexual transgression was the cause of the Flood in the time of Noah.

Regarding your more specific question, the Bible commentators, Rashi and Onkelos, explain that man is distinguished from the animals by his Divine gift of speech. The mouth is considered the "Goblet of the King." The word of G-d is to fill our mouths. If we fill it instead with refuse, we pollute the King's goblet, and lower our Divine status.

While a woman's sexual organ leads to the womb, where the miracle of life begins, its outer opening is a place of impurity, urine, and menstrual blood. Someone who engages in this practice without repenting can be sure that the holiness of his prayers will be severely hindered. Jewish Law frowns upon oral sex, and the Kabbalists stress its damaging effects, especially concerning the wasting semen in vain when performed on the male.