In the last couple of months my boy Frenchie, Otis, who is about a 1 1/2 years old, has started doing this thing where he sits on his butt and spins around in a circle. He gets an erection from it and it causes him to get rug burn on his butt. I thought it might be that he needed his anal glands released but we had that done and he's still doing it. I've also checked the tail pocket and what little tail pocket he does have is clean, though I've been wiping a couple times a week just in case. Sometimes he'll even stop while we are walking to do it. He never did this before.... Any ideas?