Well digger… :smack:
Messed up my own punch line…
I don’t know the answer, but I can tell you I’ve noticed this on myself. Most recently in a store trying on clothes. Maybe blood flow to the area is a factor?
Well, this is a scenario for one of the many uses of cats. Portable butt warmers. If you don’t have a cat, you could get one and put it on his butt. Mine can sometimes get a little careless with kneading my butt with her claws, but otherwise she works well.