Unless It's a Pleather Cow

A teen girl punches her father repeatedly in the arm.

Older sister: You know he can't feel that, right? He's wearing a leather jacket.
Teen girl: What?
Older sister: Yeah, that's why motorcyclists wear leather, so they don't get their skin scraped off when they go sliding across the pavement.
Teen girl: Oh! So if I punch a cow, it can't feel it?

--The Plaza