Hmm this is something i've always liked! It's not a very well known fetish and there isn't a lot of erotic material about it which I've always found frustrating!
But for me the fetish is the other way around. I'm a busty girl with 34DD boobs and I love it so much when other girls get jealous of my rack! I often get looks from girls glancing down at my boobs, and what makes it extra sweet is if a small chested girl is with her boyfriend or husband and he is checking out my tits
The best is when the girl notices her bf looking at me and gets mad at him!
I've had plenty of fantasies about humiliating and taunting a flat chested girl with my big tits. In a way its surprising there is so little porn about the subject!