The X Men star said he was dehydrated before a Broadway performance of Beauty And The Beast in the 1990s.
So on doctors' orders he drank a lot of water.
He said, 'Then in the middle of a song, I discovered that the muscles that you use to hold on are the ones that you need to release to sing.
'I was basically going to stand there and not sing or pee in my pants.
'Of course the show has to go on, so I peed in my pants, in red tights on stage.'
Aussie hunk Hugh, 42, told a US newspaper, 'Basically from that moment on, I can pretty much handle anything.'