For me, it started as a young child. While sitting on the toilet, I pissed up towards my mouth and sprayed my chest mostly, while tasting some of my boypiss. My father was a frequent visitor to many bars and I would go with him and play video games and such, but would always be sure to visit the bathrooms and scout out my filth. I'd scan the urinals for pubic hair I could put in my mouth. I'd lick the toilet seat clean of any stray, anonymous piss. One bar in particular had a baseball field on the property and hosted summer leagues and I ALWAYS wanted to go so I could suck strange piss off the seats. I also used to write "for blowjob notes" on the walls and would jerk off in the stalls on return visits seeing that guys had written their numbers on the wall for me. (though I never did call one).
As I got older, I started fucking myself in the bathroom with a wooden dowel. I'd pull it out and it was covered in my own shit. I smelled it and wanted to taste it, and one day got the nerve to lick it and was addicted. I fucked myself and ate my turds for my high school years endlessly. (among other perverted things)
When I was 19, I had a fake ID and was able to get into the bars. I met this hot Biker dude one night, he had to be late 30's early 40's, white dude, brown hair and a thick long bushy beard and stach. he had a leather jacket on, smoked a cigar and was in general a relaxed but aggressive man. We both proceeded to get fucked up drunk. we went back to his seedy motel room and started fuckin around and getting raunchy. He fed me piss, cigar spit for the first time and sat on my 19yr old mouth. He was very verbal and just started grunting out a fart and log feast for me. He never really asked and I never really stopped him.
I wound up eating his turds and getting smeared in his waste. When we woke up in the afternoon the next day, he was pissed at his hangover and belittled me for being such a toilet for him. We were both pretty messy still and he lit up a fresh cigar while I cleaned up best I could. He made me lick the dried shit from his body, from his bush and was becoming quite mean about it. Slapping the side of my face and pushing me towards the tub, he 3/4 squatted his hole towards me and blasted his runny diarrhea at me with no real aim, just a spray of shit. I wallowed in his filth for a while with him above me being verbally abusing me.
Today, I'd love to bump into him again, maybe turn a few tables on the evil fuck <grin>