I was coming home from the beach with a friend, her boyfriend, and her mom. Me and my friend fell asleep and when I woke up her boyfriend was rubbing my thigh. I just moved my leg and pretended I was still asleep because I was shocked. Why would he do that?

Either he's being a creep or he's...no he's just being a creep. Okay, so I kind of know what you're going through because it's been happening to me too. But mine was a bit more subtle than this, so I just usually rolled my eyes and ignored him.

First what you need to do is pay attention to see if this happens more than just once. If it keeps happening, it's a sure sign that he's being a creep. If this was just a one time thing, I'd still keep an eye on him but wouldn't worry too much until he does something like that again.

Second of all, try to think of reasons why he might be doing this. I know you asked why he's doing it but I'm sure you have suspicions of your own, right? List those suspicions and try to minimize his urge to do that based on the list you've created. Just assume that everything on that list is true just to take precautions. For example, if one of the things on the list says he wants to "feel you", then wear more conservative clothing. Wearing really showy and short clothing can be baiting him to touch you. Stuff like that.

Third of all, tell your friend. He is her boyfriend after all. He shouldn't be doing creepy stuff if he's already had a girlfriend. It's pretty much on the verge of cheating but not quite there yet. It could just stay the way it is now like with the guy who's got a girlfriend but is creeping on me, but it could progress into something more. And that's why your friend needs to be warned. (As a side note, I'm not warning my creeper's girlfriend because I know my creeper as a person quite well and he's not the kind who's willing to do anything that would get him caught, but I don't know about your friend's boyfriend, so this third thing has to be based on your call).

I hope things get better. Best of luck!