Mash job 

Repeatedly punching the testicles of a sexual partner for pleasure.

Tim:
I love when becky uses me like a speed bag.
Frank:
What?
Tim:
She gives the best mash jobs.

Mash job by Weird kinks April 28, 2022

montauk mash job 

When you are getting your your junk pounded on by a significant other (e.g., a partner, stranger, lover, hornswoggler) whose hands are sandy af.

The act of really going to town on someone's private parts with hands / feet filled with sand.

A "Sandy Handy" but with a little more gusto!

This is a non-gender bias term, anyone can give or recieve a montauk mash job as long as thier extremities are sandy and you are really "just mashing it." You also don't have to be in Montauk, or on a beach.

"Whoa look at those two homeless guys giving each other Montauk Mash Jobs under the boardwalk" -- an angsty teen witnessing a grown man receive a sand filled hand job on Long Island

"Yeah she gave me the ole' Montauk Mash Job" -- a guy with severe sand burns on his dick

Guy 1: "She was trying to grind my dick into dust with her sandy hands"
Guy 2: "So she gave you the montauk mash job"

montauk mash job by #SquidKid April 24, 2017

Mashjob 

When a (usually inexperienced) female's attempt at giving a handjob becomes messy. This often occurs under a table where the female is trying to be discrete about her act of affection.

She wasn't down for troat last night, but at least she gave me a mashjob at breakfast.

Mashjob by bmp13 November 29, 2009