They just take your headphone and tell you that they don't like it? So what? People often do that to me whenever I play my music in my car, they quibble about it or make mean remarks about it. And I have learned to ignore it.
If you like your music, then that's all you need, you don't need "friends" that come along and just take your headphones without warning and judge your music. If you like your music, then it's *your* likes and dislikes; your iPod is for *your* music, it's not an outpost for other people to put on only music that they like. Even though I have no taste for Lady Gaga or any of that stuff, I can relate in that your music is your bliss and people can't understand how you like it and how you don't see things the way that they do.
If you like your music then you listen to it, and have fun doing it! But other than that, I've gotta remark that saying "only sophisticated, sexy teens like me listen to r&b...everyone else is...eh!!!" is a pretty close-minded thing to do: it sounds like the exact problem you have with your friends, it sounds like this: "only my kind of music is good and everyone else's is weak." You can't really say that, you've got your tastes and they've got theirs, we've got ours and everyone likes a different beat, some like yours and some don't. It's different strokes for different folks, so the next time a friend judges your music, just say to them that you like it and that's that.
Good luck and I hope this helps.