During a lecture, the lecturer told the students that sperm contain glucose.
A smart-ass gal put up her hand and asked, "then how come sperm doesn't taste sweet?"
Her whole face turned red when she realised her own stupidity and she got up to leave the lecture theatre.
As she was walking out, the lecturer said, "Well, the tastebuds we use for tasting sweetness is on the tip of our tongue. Not at the back of our throat."
(credit goes to Pussyjus for the brilliant joke)
