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
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