sex twitch
A sex twitch is when you impulsively move or react to a sensation that overcomes the body and overtakes the mind to a point of completion from a sexual situation or thoughts of stimulation during sleep deprivation....
After four hours of rough, hard, hot, exhausting sex, as I lay there drained and weak, my body limp and lacking any energy my body all of a sudden jerked and moved uncontrollably in an awkward manner. My girlfriend asked me "What was that?" I said, "my body was just sex twitching!"