I've also got a PWS covering my left cheek and over half my lip, and I've never had a problem with boyfriends. I'm also 19, like you. It is quite scary to leave yourself open to someone, and to know they could hurt you with their reactions and words. But if someone reacts that way, they are absolutely not worth your time. In all honesty, I've had some boyfriends, including the one I'm with now, who have said they love it. And that it makes me different from everyone else. I know it must suck horribly, that it sometimes hurts. But if you're just worried about a boy/man's reaction, know that anyone who doesn't accept every little part of you is not worth the trouble.