nothing should go in, but playing around the area can be hot. once had a girl going down on me start to lightly lick my testicles, suck on them then went back to licking them and went on to lick on my asshole....gotta say, never thought I would find that hot, but I could find the power to tell her to stop while she was jerking me off while doing it.
I can remember the first time my wife licked my perinium. and then she took my ass. It was great and I still love it.
Yes by myself, adds a little something extra to masterbating. Would love to have a woman play with it during sex.
this is simple yes play with my ass anyone is welcome