throw a curve ball 

Another name for taking a shit. When a catcher in baseball wants his pitcher to throw a curve ball he puts down two fingers and since taking a shit is commonly referred to as "going number two" this phrase is appicable when you have to poop.

Man that coffee ran right through me. I got to go to the bathroom and throw a curve ball before I make a mess of myself.

throw a curve ball by C Floods March 22, 2011

Throw A Curveball 

To take a shit. Stems from the phrase "dropping a deuce" whereas a curveball in baseball is indicated by the number 2.

Mack: I'm going to the bathroom. Gotta throw a curveball.
Jack: Make sure to wipe.

Throw A Curveball by Bostwick_ April 25, 2021