he doesn't understand

Okay so I'm dating this guy and we haven't been dating long but he asked me if he can stay the night tonight . I'm 16 and my parents aren't too strict but strict enough to not let boys sleep over . I don't think he understands because he's 17 and he's lived on his own since he was 15 (bc family problems) but he has his own place with a roommate and so he doesn't have anyone to tell him no. Like how do I tell him "no you can't because my parents would go for that in a million years " in a nice way that won't make him want to break up with me ???