Orgasms (bit rude)
A farmer and his wife were lying in bed one evening; she was knitting and he was reading the latest issue of Farmer's Weekly.
He looked up from the page and said to her, "Did you know that humans are the only species in which the female achieves an orgasm?"
She looked at him wistfully, smiled, and replied, "Oh yes? Prove it."
He frowned for a moment, then said, "Okay."
He then got up and walked out, leaving his wife with a confused look on her face.
About an hour later, he returned all tired and sweaty and proclaimed,
He looked up from the page and said to her, "Did you know that humans are the only species in which the female achieves an orgasm?"
She looked at him wistfully, smiled, and replied, "Oh yes? Prove it."
He frowned for a moment, then said, "Okay."
He then got up and walked out, leaving his wife with a confused look on her face.
About an hour later, he returned all tired and sweaty and proclaimed,
Spoiler: