To fail suddenly, unexpectedly and humourously without you or other surrounding parties initially realising your mistake.
*Following a breif period of silence where it dawns on everyone what an idiot Robin has just been*
Stu: Hey man, you're an idiot, you shot a cow on that one!
The Urban Dictionary Mug
One side has the word, one side has the definition. Microwave and dishwasher safe. Lotsa space for your liquids.
Buy the mug