Realistic:
Being a human toilet for many various girls to use. They would shit, piss and occasionally spit and vomit into my mouth. Would also love if they force their sweaty feet or smelly high heels on my face and into my mouth. Old, young, white, black, with hard solid shit, with diarrhea, everything.

Impossible:
An extension of the realistic one - perhaps I'd be a toilet 24/7, won't eat anything but shit and vomit, my legs and arms would be cut off and my belly would be very swollen from all the shit. Shit would come out of my nose and some of the girls would occasionally beat and kick the shit out of the trash that's left of me.