Why do couples sleep together?

I'm so serious. My mom doesn't sleep with my dad (he sleeps in his office usually) so it's never really been something I ever considered until I learned it's a "normal" thing apparently. And why would any woman? Every time you drift off to sleep with a man next to you, you're risking the possibility that he might have sex with you without a condom. It's a really irresponsible and frankly dangerous practice and it feels like a form of self harm. Like even if your man "respects you too much to do that" there's still the risk of the autoimmune diseases that will be racking up from the underlying stress worrying that he may or may not slip up. And the liability period on a man never expires for this kind of thing.