rectum plectrum
Example:
John: I was thinking of buying some assless chaps, and also a rectum plectrum. What do you think?
Dude: Uh, OK, dude starts running as fast as he can in the opposite direction.
John: I was thinking of buying some assless chaps, and also a rectum plectrum. What do you think?
Dude: Uh, OK, dude starts running as fast as he can in the opposite direction.