My friends always feel the need to insult me when I make an effort to look good!?

Like the other day I had used fake tan, but it wasn't dark at all, it was just glowing, and made my skin look better (my mum wouldn't have let me leave the house if it looked bad believe me!) and as soon as I walked in the ring leader of my friends sits there and goes, oh have you been fake tanning, and they'll all sit and laugh at me, and then told me I looked tangoed which I didn't! It's not just this it's every little thing, like new clothes, a new pair of earrings, etc. And it makes me really self conscious, and they know what there doing. Then I'll go quiet and get pissed off, and they'll start going 'oh, why are you in a mood?' and just urghh. I'm sick of it, because I went to see them feeling great and went home feeling like complete and utter shite. I bite back, but they still persist in doing it! =[