Why call the small butt “flat”? Flat is a shape, not a size. In reality, a small butt is actually *more likely* to be round than a jiggling gelatinous one (which sags due to gravity; shifts due to inertia).
I truly cannot fathom why a big butt would ever be seen as an unattractive feature… extra fullness in the hip area has always been a sign of health, fertility, and femininity, so exactly what is the appeal of a flat butt? I’ll never understand…