Most often witnessed in subways. An acceptable but lesser used version can be used to describe rubbing ones own ass in a public place thereby making others feel uncomfortable.
(eg Spunking used to be my favorite hobby until I found out that all the times I've been maced can cause blindess)
“Some chick asked me to spunky her the other day”
“I had some great spunky the other day”
“Are you the spunker or the spunkee?”
“She sniffed my ass so hard it was like she was spunking”