When you are a man! A real man and your manliness is so huge that you physically make girls throw up during/after sex.
IE: you have a huge penis.
Pull over I need to throw up- Girl1
Why? - Girl2
He just hit my Jermey Reflex- Girl2
Wow, he's huge- Girl1
You mean he hit you're Jermey Reflex- Girl2
Yeah it was like a Louisville Slugger- Girl1