An *adult* said that to you? People can shop in the ritziest of places, but it doesn't automatically give them any class.
I don't even think about comebacks anymore. They're not even necessary. Just looking them in the eye with an incredulous look and walking away shaking your head will instill more shame in them than anything you could ever say. Silence speaks louder than words.
I'm one of those who wears high-cut bikinis out of fear that I'll show some crackage. I had a pair of DKNY jeans once that fit most awesomely, until I shrunk too much I had to give them away. It was the only time I've ever regretted losing weight. I'm sure I could get another pair, but I can't bring myself to spend over $40 on jeans these days. I'll wait till I'm down another size or two. But if you're in the market to spend a little, I loved my DKNY Soho jeans. Find yourself a pair and be in bliss.

They go up to i think a 16 at Macy's or Dillard's - I forget which.