“A guy walks into a bar...” is a typical form of what has been called the “bar joke.” An anti-joke version is:

“A janitor, a waitress, and a bartender walk into a bar. Then they open for the day.”

The joke was posted on Reddit—Jokes on December 28, 2017. “A bartender and a waitress walk into a bar. ‘Almost opening time,’ says the bartender. ‘Yep! I’ll get the oven going!’ replies the waitress”—a similar version—had been posted on Twitter on March 19, 2014.

“A bartender walks into a bar. He works there” is a related anti-joke.


Twitter
Troy Blackford‏
@TBlackford3
A bartender and a waitress walk into a bar. “Almost opening time,” says the bartender. “Yep! I’ll get the oven going!” replies the waitress.
5:58 PM - 19 Mar 2014

Twitter
Troy Blackford‏
@TBlackford3
A bartender and a janitor walk into a bar. “Time for work!” says one to the other. #PunchlineRemovedToProtectTheInnocent
4:55 PM - 20 Aug 2014

Reddit—Jokes
A janitor, a waitress, and a bartender walk into a bar.
submitted December 28, 2017 by Mechasteel
Then they open for the day.

Twitter
Tyrell Kline‏
@kline_tyrell
A janitor, a waitress, and a bartender walk into a bar. (Link to Reddit.—ed.)
7:48 PM - 28 Dec 2017

Twitter
Brooke Madden‏
@BrookeMadden18
A janitor, a waitress, and a bartender walk into a bar. (Link to Reddit.—ed.)
8:45 PM - 28 Dec 2017