This is about the crease across the gut right?  I've noticed this frequently on female fatties and have been wondering about it. I have two competing theories about what it is.  1) It is a product of how a fatty's body distributes fat. When there is that much adipose to deal with it starts weighing and folding over in interesting and unexpected ways.  2) It is the permanent crease in the incredibly soft fat from squeezing into too tight jeans. Every time I see one of these it looks to be right at that spot that fatties like to wear their jeans. After tucking in the fupa of course.