I have a bit of a different perspective since I am not a Catholic yet but am starting to learn about Catholicism. I am currently non-denominational, but I’m waiting for RCIA to start and I have weekly meetings with a Deacon at my local Catholic church to discuss Catholicism. So far I have found certain things about Catholicism that I like, but others that have me concerned. One of which is the Catholic notion that any male ejaculation outside of the vagina is a mortal sin even if you’re married (Venial sin I might understand, but mortal? Really?). Protestants are virtually unanimous on the agreement that any sexual act within marriage is permissible so long as it’s consenting by both parties, and doesn’t involve bringing in more people (adultery) or pornography (lust). This is because the Bible never states that oral sex, anal sex (between heterosexual couples. What verses refer to sodomy are in the context of homosexuals only), manual stimulation (by the partner), or any other such like is a sin. The Bible says that a married couple will become one flesh, but it doesn’t say HOW they become one flesh. So my question is, what is the biblical basis for this seemingly rash judgement on the part of the Catholic church? I’ve seen other forum posts talking about “natural law” and saying that since such acts violate “natural law”, that’s what makes them sinful. So what is “natural law” to begin with, where is the concept of natural law mentioned or expressed in the bible, and what is the biblical basis for the Church’s interpretations of natural law? Furthermore, I discussed this topic with my Deacon briefly as well. He was confused, and said he had never heard of any specific Catholic doctrine regulating physical relations within marriage other than the above-mentioned examples of adultery and lust. He said to the affect of “We don’t tell married couples what to do in the bedroom. That’s between them and God.” So how could a Deacon not be aware of these restrictions, especially since he’s married?