Humans are one of the few species out there that have sex without the express purpose of having children.
It's like saying you are not eating because it feels/tastes good, you eat because you "want" nutrients. Absolutely retarded view. Hunger is natures way to "make you" go and eat food. Same with being horny, it's natures way to "make you" go and procreate.
Your understanding is off, primarily due to rape mostly being about power over another and indulging in that.
This "power dynamic" thing is a lefty/feminist cope to say
"muh, he was stronger and had power over me" when their monkey branching attempt didn't turn out the way they wanted to (when talking about male on femal rape). No, rape happens because the man just wanted a shortcut, no commitment and has no care for the victim when they didn't want to comply with their hedonistic behaviour.
Do you think animals have "consent"? Most of them don't (very few mammals have
that), they just "rape" and have kids and life goes on. Falls in line with r/K selection theory, see it as
"just rape vs. time consuming commitment". Look at different races and their rape and single mother statistics, should give you a hint that what I'm saying is true even amongst "humans". If there was absolutly zero (evolutionary) rewards for this, it wouln't be as common, but here we are.
Quite frankly, rape being illegal means you'd be quite stupid to leave DNA evidence behind, in the first place.
Most of them are that actually that retarded. Again, look at the racial statistic, not really the most brightest (on the IQ and on the skin melanin charts) "people" doing most of the raping.
It's a fact that there are creatures out there that has been walking around this earth, winning the evolutionary game (having kids) with this strategy. You have to be retarded to think that there are some humans (on an individual level) that don't have this behaviour too.
TL;DR
Sex is about having children in the end, at its core.