Is my gf a slut?

Not tryin to be rude or anthing but bro, you relize that you pretty much know nothing about the situation. My advice is i don't know........ask her maybe?! Or maybe your friend?! The only people that know wtf happened is them. You can't tell if she's a slut if you don't even really know what happened between them............hello, common sense?! ASK THE GIRL WHY HE WAS AT HER HOUSE.

They could be related. But you should ask your girlfriend about it.