I note the plural and have to ask...you keep a spare rear end?
Guessing this is just an Americanism :)
Don't you also have a left butt and a right butt?
Um...two butt cheeks, yes. But they are both part of the one butt, so to speak (in Australian, anyway).
Well yeah, it's the same in American, I'm just not very good at American.
I was wondering about that word too. It's not an Americanism, I think it's just a Cristina-ism.