Frequency


The night school psychology class were studying human reaction to sexual 
stimuli with particular regard to the frequency of intercourse. The tutor
began with a few questions: "How many of you here have sex once a week?" 

Twenty hands sprang up.

"And how many of you do it once a month?" 

Ten hands were raised.

"Once a year, anyone?" asked the tutor with a grin.

The class was surprised to see a gentleman at the back, beaming and looking
happy as could be, raise his hand into the air.

"If you only have sex once a year, my man," said the tutor, "why are you 
looking so pleased with yourself?"

"Ah," said the man, "Tonight's the night!"