Sneaky Jack 

When a guy jacks off in bed while his partner is asleep

Girl to friend "I woke up last night to my guy doing a sneaky jack"

Guy to friend "I couldn't get my girl to wake up last night, so i had to do a sneaky jack"

Sneaky Jack by Bigworm13 October 3, 2010

sneaky jackson 

A Sneaky Jackson involves sneaking a flask of jack Daniels into a club, sneaking off to the bathroom with a girl and after you cum in her mouth you both take a shot

"Damn bro, I just did a Sneaky Jackson in the bathroom with Vanessa"

sneaky jackson by Ramhoe July 3, 2017

Sneakajack

The action of covertly masturbating with others around. Most commonly perpetrated by individuals taking part in a point based masturbation game. The more unaware individuals around when sneakajacking the more points received by the sneakajacker.

"The secret service failed to thwart my sneakajack while I was sitting inside the podium while the president gave his last speech about the war."

Sneakajack by SheriffKLap August 31, 2013