One of my buddies that I know wants to move into a place with his girlfriend who he has been dating for like a year, they are both 19. I can tell this chick will cheat on him in a second and I'm sure she already has she even has all put her hand on my thigh right infront of her boyfriend, yeah it was weird. This guys a total chump and hangs out with her everyday of course and I keep telling him not to do it and how it's only going to hurt him but he wont listen. I'm wondering what are some of the reprucutions of moving in with a girl like this and how can I convince him not to do this?