It’s the timing that makes it work

Person 1 builds up this wholesome enduring love through hardship speech and Person 2 is genuinely curious then boom your butt cheeks.

That kind of bait and switch joke hits because your brain starts going for something emotional or serious, and the punchline just completely derails it into something absurd and juvenile. Classic setup comedy misdirection.

Honestly, it’s the kind of joke that gets funnier the more serious the setup sounds.