The act of having a convulsion like reaction immediately after having an orgasm. This usually means the orgasm was very very good.
After the orgasm, I began to have a cumvulsion as my body twitched and jerked uncontrollably.
by FrankieV September 02, 2009
That blissfull moment during a bj when you start to orgasm and the girl starts sucking harder and your head and legs start involuntary shaking.
You start cumvulsions like your dick is licking a nine volt battery.
by The Regal Beast December 06, 2013