Sexual behaviour
A leading professor of sexual behaviour is giving a lecture to his students, explaining that peoples overall disposition is directly related to the amount of times they have sex.

"For instance, all those people here who have sex once a week, raise your hands". Quite a few of the students with beaming faces raise their hands.

"Now all those people who have sex once a month raise your hands". A few of the more glum students hold up their hands.

"Now the people who have sex only once a year raise your hands" One or two really miserable buggers raise their hands sheepishly.

"Now anyone who only has sex once every ten years raise their hands" A Guy in the back row with a beaming face and a grin from ear to ear jumps out of his seat and gleefully shouts" Me me me"!!!!!!

The professor is astounded by the man's joyful look, "You only have sex once every ten years"? he inquires
"Yes indeed" says the man barely containing is glee,
"Well why do you look so happy"?

"IT'S TONIGHT, IT'S TONIGHT" replies the man.