Neck Butter 

The foamy build up beneath the foreskin of a nasty penis, usually during intercourse or masturbation. Really gross if left to ferment too long.

She thought twice about giving him head when she saw and caught a whiff of his neck butter.

Neck Butter by Davefpsycho January 5, 2011

butter neck 

similar to turkey neck, butter neck is usually used to describe an older person's neck that is so engorged with fat, that you could scrape the butter off that seeps out of the neck pores and put it on toast

Pat's butter neck is especially swollen today.

Yeah dude, she just finished a double big mac.

butter neck by d-large March 9, 2011

Peanut butter jelly neck 

Crusty neck

Go wash your peanut butter jelly neck

Peanut butter jelly neck by Cuchiecoo June 28, 2018