Pain in The Sack

When someone is always trying to one-up you.

Guy 1: "Dude stop lying we know you didn't sleep with Kayla first."

Guy 2:"Yeah I did!!! She was wetter than a raw oyster"

Guy 1:"Bullshit you're just trying to one-up me... I fucked her first."

Guy 2: "Man you're a Pain in The Sack. Ask her sister!"