The Universal Bullshit Detector Watch does not actually detect falsehoods. We didn't want to inconvenience the small percentage of readership that sometimes takes these trifles a tad too seriously. As a general rule, any electronic depicting a cow's arse is not worth one's emotional investment. But to each his own.
The $39.95 Universal Bullshit Detector Watch can tell time, but it can also make "moo" and "poo" noises at the touch of a button. According to the manufacturer, your friend will question from whence came the sound (and this is when you come in):
"Oh, my deepest apologies Philip. I seem to have left my bull...pfff...haha...one second...hahaha...I'm ok...I seem to have left...ooh, spit my milk a bit...I...I seem to have left my bullshit detector on!"
And then Philip will feel most foolish.