Does s#x hurts for the first time?
Depends. Depends who has what and what's going where. Normally it's not supposed to. If it does, it's bc the body isn't relaxed and there isn't enough prep (foreplay) and lubrication. It's especially essential to do prep if it's your first time. A partner who isn't willing to do that for you, is not a good partner. Sex education is important, regardless of sex or gender.
But don’t people who get turned on by being beaten or choked often have a dark childhood involving abuse, rape, or violence? I didn’t know much about this either, but I’ve learned so much from reading manhwa. I guess it’s only true for some people? Do people who were abused in the past develop these kinds of turn-ons because of their experiences, or is it just something that happens in manhwa and not necessarily in real life? I really hope that’s not the case, because so many dark things I’ve read about in manhwa have turned out to be real, and it’s honestly shocking to me. I just hope this isn’t one of those things.
No, for some cases it could be. But I'm a living example that these are irrelevant. I would say it happens naturally for some and for others like you said it's a coping mechanism of like a way to gain back control. Plus real life is way more complex than any manhwa or manga.