A penis that appears small but grows large when erect. The term sleeper is in reference to a car that appears to be stock and slow looking, but has a powerful engine under the hood
You should totally hook up with him, I heard hes packing.
My friend is in water polo with him and he sees him in the locker room all the time, he said its tiny.
A drawing of a penis in another persons school book that is drawn far through the book so that it is designed to be found and cause shock weeks or months after it is drawn, much like a sleeper agent.
Harrydiscovered the sleeper dick in his physics workbook, three months after we drew it.
When a normal or below average looking dude has a hella’ dick and knows how to use it. It must be both big in size and a great fuck to meet the requirement.
See also: sleeper cell fuck, when the dick just isn’t impressive.
Holy shit, Johnny is a total sleeper cell dick. That thing had to be at least 7” girth and god damn did it scrape all the right places.