When the female is going so wild in sex that she slides off the slippery serpant and gravity takes it toll, thus resulting in her colliding with the shlong, causing a Cuntknock.
Darren - Dude gertrude was bloody mental in bed last night.
Josh - Dont talk about last night.. i got cuntknocked.
Darren - Ohhh bad times man sorry to hear it.
Josh - Yeah.. it was the worst.