Apparently somewhat on the fringe in gay circles, but involves using thin, cylindrical items (thermometers, wire, rubber worms, etc.), and inserting them into the dick hole. Over many months, continue to gradually ream out the hole-at-the-head with larger items.
thus ultimately allowing your "buddy" to obtain the goal of fucking your urethra. Wow!
When someone is up in your shit and pissing you off asking what you're doing, give them this answer to shut them the fuck up.
b: yea, hi
a: doing anything interesting?
b: no, move along please
a: so what you got there sport?
b: nothing, I told you. Please go away
a: c'mon, lemme know what you're doing
B: FUCK OFF!
a: I will, but I wanna know.
B: Okay, I'm cock-stuffing. Is that the answer you wanted to hear? COCK-STUFFING!
a: okay, I shouldn't have asked, jeesh.