The rude joke you’re referring to is from a scene in How I Met Your Mother, specifically the episode titled “Not a Father’s Day” (Season 3, Episode 8). In this episode, the character Ted Mosby tells a joke that initially sounds innocent but ends with a punchline that’s unexpectedly crude.
Ted starts telling a story about a joke his friend Marshall told him, involving a scenario where two people are in a situation, and it leads to a punchline about “a chicken, a cow, and a goat.” It’s a setup that seems harmless, but when Ted eventually tells the punchline aloud, it’s more risqué and vulgar than expected.
In general, the show often uses humor that can be edgy, with characters making innuendo or jokes with double meanings. However, the joke you’re referring to is particularly notable for being a bit more explicit than the typical humor in the series. The joke itself is an example of the playful and often inappropriate humor that How I Met Your Mother became known for.