this one had long lasting repercussions
all from one mate, admittedly several years ago:

biology teacher: "whats the name of the white fluid found in rotten teeth?"
mate: "semen" (the mind boggles)

another:

myself and several others: random pisstaking of mate

matey boy: *Enraged* "Are you guys gay or is it just me?!"

the mileage on that one has been priceless
(ianfidel, Sat 8 Jan 2005, 0:47, Reply)