When you're jerking off (right before you get a potential cactus jack) a jack stranger is when you sit on your arm and then masturbate so it feels like a stranger is jacking you off.
"Johns wife wasn't putting out so he enjoys giving himself Jack Strangers when she's being frigid."
by CookiesandCream2 October 30, 2013
1 more definition
When you masturbate with your numb arm you are giving yourself a "Jack Stranger."
I'm horny and lonely.. I think tonight calls for a Jack Stranger!
by Spankamonkey December 07, 2013