Cock knocking involves two males. One male has "trained" or "stretched" his penis hole, commonly using house hold objects such as markers and progressing to larger items, etc.
The second male inserts his erect penis into the urethra of the male with the "stretched" hole and they proceed to have penis to penis sexual relations. often resulting in disturbinginfections.
earl: ballsack
crabman" sperm bank (even lounder)
Randy: collin has a small fallis (lounder)
Earl: BALLSACK :teacher hears it and sends him ou
everbody laughs while the teacher trys and controls the class who by now are all doing it
teacher: ohhh stop cockknocking