One time at a 13th birthday party we were at an arcade at a big shoppng mall called "west town". One of the other kids came up and said, "there is totally a guy jerking off in the bathroom stall."
So of course we all had to go in to investigate.
In pairs we went in and reported back.
Dude had nice shiny business shoes on and was facing the stall wall and obviously trying to yerk silently. And failing.
So we call waited outside and when he came out we all cracked up and he realized he had been made. He was really well dressed and obviously some sort of professional.
Anyway from then on we would always say, "going to west town" or, "going to the mall" to mean jerking it. "Ah I couldn't get a BJ from Annie so I am going to west town." or "Man that kid is ALWAYS going to west town, have you seen his VHS collection?".
It also got funny when other people who weren't in on the joke would be like, "Oh I am going to the mall between classes, wanna join me?"