You hear the phrase, “sex is natural," and variations of it quite a lot. This is a claim many people and institutions make. This argument is often used to justify certain sexual behavior—and its inverse, that a particular sexual behavior is "not natural,” is often used to condemn other sexual behavior. This is a confusing concept, clearly open to all sorts of interpretations, if my Google search results are any measure of the English-speaking human psyche.
When people say sex is natural or that certain types of sex are natural, I honestly do not understand what they are trying to communicate. What do they mean by “sex”? What do they mean by “natural”? Do they mean it is involuntary, like breathing? That we just inherently know about the birds and the bees? That we know how to have good sex and healthy sexual relationships? All this, you and I know, is not true.