Do you ever tell some one you have had an accident in your underwear?

The reactions are amazing, ranging from ignoring you to offers of sympathy and help.
Expressions I have used:
I’ve had an unexpected bowel movement
I’ve soiled my pants (or self)
I’ve been rather childish where are the toilets
I need to change my pants
I’ve misjudged a fart
And the classic, I’ve messed myself

What do you say?