>>3249338I assume you are a guy. (I hope correctly) In that case, that's perfectly natural. the "Harem" instinct in men has been ingrained since before we learned to walk upright. It's the way our species is wired. Males want to spread their seed to as many eligible females as possible.
In this case, you mentally put yourself in the protagonists place. They aren't fucking him, they are fucking YOU. There are no other males to compete with, you've got the harem to yourself. Unsurprisingly, that is far more enjoyable a fantasy than one where you must share the women with another male.
So no big deal, you're a normal dude. Now excuse me, I have to get back to fapping.