Knuckle Crust 

Dried semen. When remnant semen dries on the fingers after fapping and busting a thick nut all over the hand.

Is that dried skin on your fingers?

Naaahh. I just didn't wipe my fingers to good after fapping this morning. It's knuckle crust.

That's fuckin nasty braaaahhhhh

Knuckle Crust by Eaton Holgoode May 9, 2017

Knuckle Cluster 

The name given to a gathering of lesbians, typically consisting of at least three.

Bro, did you go to that party last night?
Yeah, there were a ton of lesbians, it was a real knuckle cluster.

Knuckle Cluster by chevyboyusa February 4, 2021

the knuckle cluster 

when you fist someone with a handful of popping candy

I gave Ellis the knuckle cluster behind maccies last night

the knuckle cluster by bigjigga69 May 22, 2021

knuckle cluster 

when you put popping candy in your hand and fist your partner

I gave Ellis the best knuckle cluster last night behind MacDonald's

knuckle cluster by bigjigga69 May 9, 2021

Knuckle Cluster 

When you're in bed with your man and he lodges his entire fist into your cooch. he then squirms his hand around until he sees his knuckles through your belly. Once seen they instantly cum.

Ronald: Did you hear? Samantha got knuckle clustered by David
Arnold: Really?
Ronald: Yeah. She died mid-way and he sat there cumming. He soiled the bed sheets completely white
Arnold: Damn. It was good when I railed her ya'know?

Knuckle Cluster by I'mAGlugGlugVacuum6900;) January 11, 2023

Crusty Knuckle 

After someone has fisted another person, they leave their hand uncleaned for a while. The fluids, dry and harden on the hand, forming a Crusty Knuckle, or Crusty Knuckles depending on the severity.

Jasmin fisted Leeroy. She left her hand overnight an the shit hardened. In the morning her hand had turned into a Crusty Knuckle.

Crusty Knuckle by L.Jenkins January 11, 2012

crusty knuckle 

A crusty knuckle is when you have your girl stimulate your prostate by shoving her middle finger up your anus. Look at her knuckle once she is done.

I blew a load so hard while Christina was giving me a Crusty Knuckle.

crusty knuckle by John Chapman June 1, 2007