Sex with partners you know, love, and trust is very hot. Get to know each other well and you can know personalities and bodies. You can use this knowledge and intimacy to tailor your sexual experience to perfectly engage your partners and make it hot as fuck. But do you know what else is hot as fuck? Having sex with a total stranger.
Sex with someone you don't know well (or at all) is full of uncertainty and danger, and that danger is so damn hot. You don't know what you're going to find under their clothes. You don't know if they're going to be gentle or rough. You don't know if they're safe. You don't know if they know how to fuck. All of these unknowns are so hot! Is hooking up with a stranger safe? No way! Does that make it even hotter? Hell yes!