Problem With Beautiful Girlfriend

I have a big time problem with my girlfriend. She is 21, very very petite, with just barely there puffy areolae and nips, no tit growth at all. She is totally beautiful with long, soft brown hair. She is thin, petite and keeps in great shape. So, what's the problem right? She honestly looks like she's 12 years old. Even at the beach, or anywhere. People stare at me like I'm a perv dating a girl instead of a woman.

My friends were the same, and their girlfriends were terrible about it, till they found out she's old enough to drink and has a real ID. She graduated college and to be honest has appeared in some porn for those who like the young stuff. We've been going out now for about a year, and she is incredible. She is wild in bed and can't get enough. She cums super easy, and let me pop her in her pooper too. She will wet herself, go in public and exhibit herself, fuck in public, be a sex slave for a weekend, and loves an over the knee spanking with hand, belt or paddle, you get the idea. She is perfectly suited for me, but even with me sometimes I'm fucking her and look down, pinch those barely there nipples and see this little girl looking up at me.

WOW, helluva dilemma. Love her, don't want to stop having sex with this dynamo, but everyone thinks I'm perving on some 12 year old or something.