I'm reminded of a story that my mom told me as a kid, this doesn't have to do having a poorly conceived cosmetic procedure done to make your butt big, just a weird peril of that kind of body shape.
Mom used to take me to the YMCA in Harvey when I was a little kid for swimming lessons. She said that there was this one lady, very thin and normal on top but with large fatty butt, tummy and thighs, y'know, "pear-shaped", who almost drowned once when she was there in the late 1960's. The woman had wadded out into deeper water and tipped over, capsized. Most of her bouyancy was on the lower half of her body and she almost drowned because she couldn't right herself in the water, it took several other women to help her out. It's just not healthy. Don't go near deep water if you've got a big butt.