main vein 

Penis.

Slang word for penis.

"Be right back, I'm gonna go drain the main vein".

"I drilled her with my main vein".

main vein by mickyxtee May 9, 2009

Main Vein 

The largest vein in the penis. Once the penis has become erect, the blue/purple vein becomes clearly visible.

"Seeing that chick naked got me so hard that my main vein was just bulging!!"

Main Vein by PMchoisi June 8, 2009

Main Vein 

The large vein that travels the length of a cock. Instrumental in delivering blood from the central artery during erection.

My cock was so hard, my main vein was swollen with blood.

I saw my heart beat as the main vein of my cock pulsated with blood.

Main Vein by Tony from the Lido September 21, 2011

Main vein 

A word for penis

Gonna go drain my main vein, back in a few minutes.

Main vein by The¥/ May 11, 2023

main vein pain train

An event which occurs when one woman is with five men at the same time. One in the pink, one in the stink, one in the mouth, and one in each hand.

Did you see Jessica go off with those five guys last night? She must have ridden the main vein pain train!

main vein pain train by Job Skywalker September 8, 2011

Drain the main vein

Slang for "Urinate"

"The Main vein" being the penis of course.

"I gotta drain the main vein something fierce"

Drain the main vein by Doc Evil July 24, 2003

the main vein 

Penis

My bladder is so full I think its time to drain the main vein

the main vein by Xeroman January 31, 2016