Spy: Hahaha.
Me: What?
Spy: Time to pick up your mother.
Me: Oh no....
Listen up, buttercup. This "yo mama" joke is about as fresh as week-old roadkill, but here's the stink of it: The spy is saying that he's gotta "pick up" the other person's mom, implying that she's easy, like some cheap date. Get it now, genius?