I was raised Jehovah's Witness. They basically forbid premarital sex, masturbation, oral sex, anal sex, and "unnatural" sex acts (i.e. BDSM/homosexuality/polyamory etc), and even have had a history of announcing from the platform that you could lose "privileges" if it became known you participated in "unnatural" positions like doggie style within your own marriage.
I wish to god I was making this up.