a lecturer was standing in front of a group of women trying to give a lecture on involuntary spasms within the human body

having tried to gain the noisy and disruptive class time and time again with no success he finally cracked

walking over to one of the noisier women in the front row he asked the question

"WHAT DO YOU THINK THAT ARSEHOLE OF YOURS IS DOING WHEN YOU HAVE AN ORGASM????"

to which the very surprised young women replied

"STUFFED IF I KNOW, HE'S PROBABLY OUT FISHING"