i still think the daddy who was role-playing "uncle, nephew" tops it. most of the sissies know this story, but you may not Caedmon.

i was in the shower, suckin' some cock, and squattin.

"Yea, you like that boy? You like that cock?"
(muffled aggreeance)
"Yea, I like that too. You gotta shit boy?"
(i stare up inquisitively, mouth still full)
"Why don't you take a shit while you suck my dick?"
(i look up trying to tell if he's serious or not. does he know that i will actually do this if he asks me to? i do kind of have to shit, actually. hmm. my god yes, he is really serious. ok, here goes)
(explosive diarrhetic shit from being both lactose intolerant and addicted to dairy)
"Awwww, yea, yea shit, boy, that's a good boy, keep suckin' uncle's dick while you shit"
(at this point, i feel like Dawn Weiner being forced to shit in Welcome to the Dollhouse, and find myself blushing oddly, but also looking back at my shit with some sort of pride. it is quite a lot of shit)

of course, that moment passed, and he didn't find it too hot that the shit did not immediately flush through and go down the drain. well my god, this wasn't my first time shitting in a shower, and i could have told him that. the water ran over it for five minutes while we cleaned up, and he had a hard time looking back at the small pile of feces turning soft and running down the drain in small chunks.

for the rest of our drunken groping, he never questioned my commitment to perversion again.