extra-sausage
Explanation
The Joke
A woman receives a pizza with "extra sausage" and the pizza delivery man launches into an unsolicited, detailed explanation of what sausage actually is: not whole tubes of cured meat, but small bits of low-quality, safely-prepared frozen meat in casings. He then adds that if she were "planning to seduce" him, she should have specified Italian sausage and paid extra. The woman asks if he's "by any chance a bachelor of the arts" and he responds that "the metaphor ain't apt, this junk stays untapped" — a self-deprecating joke about his lack of romantic prospects.
The Humor
The comic plays on the well-known adult film trope of pizza delivery as a setup for seduction (the "extra sausage" double entendre). Instead of playing along, the delivery man pedantically deconstructs both the literal nature of sausage and the metaphor itself, killing any possible romantic subtext with excessive factual detail. The escalation is that he then critiques her seduction technique from a culinary standpoint, suggesting Italian sausage would have been more appropriate. His final rhyming admission that he's romantically unsuccessful despite (or because of) his over-analytical nature is the cherry on top. The comic mocks both the cliched porn setup and the type of person who can't resist correcting things even when it's socially counterproductive.