Nut Knuckles 

When a man masturbates and ejaculates and the sperm (a.k.a. nut) runs down your knuckles of the hand of which he was mastubating with.

Joe: Hey man did you fuck kelly last night?
Drew: Nah, bro she said she didn't want to at the last minute.
Joe: Damn that sucks. So what did you do then?
Drew: Well since she gave me blue balls I had to masturbate to relieve stress, and I accidentally gave myself Nut Knuckles.
Josh: You didn't have to tell me that.
Drew: Hey man you asked.

Nut Knuckles by Negros Love Maple Syrup October 4, 2016

nut knuckle 

n. slang 1. When a man pulls his ball sack and one nut out of his unzipped pants, making sure to sqeeze the skin behind the nut to it's bulbous glory. Said nut knuckle is usually pulled out to an unsuspecting participation as a humiliating joke.

Hey mike look at my finger I think i cut it. *pulls out the nut knuckle as mike turns to look*

*mike sees the knuckle and is in stuper*

Fuck off you nut knuckler!

nut knuckle by Necremis December 16, 2005

knuckle nut 

A jack off. Or, ejaculation caused by masturbation.

"Quit being a knuckle nut and come help us". Or, "I had a knuckle nut in the shower this morning".

knuckle nut by TheParrott May 19, 2010