Bible doesn't mention oral sex so it must not exist, or at least not be any more objectionable than hugging and kissing (which it does mention.) Though the scholarly defintiion of sodomy is anal intercourse, beastiality, and oral copulation, the Bible mentions the other two, but not oral copulation.
Modern interpretations regulating sex between married men and women permit anything and everything since the only prohibitions mentioned are incest, with a woman during her menstral cycle, and adultery. But if married, you can enjoy anything at all since nothing is then forbidden. Especially given how specific the Bible is forbidding other sexual acts, we can only conclude that if nothing's forbidden marrieds, then nothing is forbidden.
The sin of Onan is coitus interuptus. Withdrawing the penis before climax to prevent pregnancy. But since sex is for fun as well as procreation as evidence by the commandment a husban shall not diminish his wife's food, clothing, or sexual satisfaction, sex for un is implied. But if coitus interuptus is forbidden we assume oral and anal intercourse are permitted.
