This is the earliest joke I remember my dad telling me (slightly NSFW)

A man goes for a wonder through a quiet part of town he's never been. Its late and there aren't any shops open. After awhile he gets a strong urgue for a shit. He looks around but sees nowhere to go so he continues walking. Ten minutes pass and his uncomfortable feeling is overwhelming. He feels like he's going to shit himself any second. He stops and spots a bar across the street. He hobbles over to it trying his hardest to old his waste in.

He bursts through the tavern doors. The bar is dank and smells of stale beer. It looks completely empty.
"Hello?".
There's no answer. He spots the toilet door by the end wall and makes a dash for it feeling like he's going to explode at any moment.

He swings the toilet door open revealing a single toilet. He was a bit thrown back by this but time wasn't exactly on his side, he needs to get this demon out of him now. He throws the toilet door closed, pulls his pants down, turns around, and before he could even get his arse on the seat, all hell brakes lose. He unloads what feels like the biggest shit of his life. Nothing in the world mattered at that moment, he had done it.

Sitting there on his throne, sweating and feeling like a million bucks he reaches for some toilet paper.
"Oh shit", he thinks.
There's no toilet paper. There's no toilet paper holder. There's not even the cardboard roll left. Panicking and frantically looking around for anything to wipe with he spots a hole where the toilet paper holder would be. Above it is some writing.

"Wipe your ass with your finger, put it in this hole and it will be magically cleaned".

"This must be a joke" he thought.
But, fuelled by desperation and curiosity he goes for it.
He scrapes as much shit as he can off with his index finger. He holds his breathe, aligns his finger to the hole, closes his eyes, and slots it in.

What he didn't know was at the end of that hole was a long, sharp, pin.
He pricks his finger, let's out a yelp, and without thinking he shoves his finger into his mouth to soothe the pain.
There, clean.