=\ i used to bring home my stray friends and still do if they need it, but they were all clean and took care of them selves. Actually they were all teenagers with jobs... they just needed to get away from abusive parents....
my mom hated sharing our space but let it happen because they had no one to care about what happened to them. She actually didnt mind them after awhile though cause they all kept the house clean for my mom though and even bought there own food and chipped in for bills. She actually missed a few of them after they left.
If this guy can't respect your home or rules then he doesn't deserve to be there. 15-20 year olds can pull their own weight and actually make a good lasting impression on my mom. So much so that if they ever needed to stay with us again she'd welcome them. if he can't do that he should leave immediately.