It is when you take your dick tuck it inside of your self when it's limp and push your legs together to hold it inside. Then start walking and open your legs so it goes SPROING!!! (Usually done by little children)
I was bored one day so I tucked in my penis and watched it go sproinger.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi