Steatopygia is when someone has really big buttocks, like a very big bum. Imagine a pillow or cushion that is really round and large, that's what it looks like. Some people have a gene that makes them store extra body fat in their buttocks area, which can make them appear bigger than others. It's a natural variation in human body shape, just like some people are taller, shorter, or have curly hair. It's nothing to be ashamed of or teased about, it's just a part of your body that makes you unique.