Bouncy castles . . . ?

OH dear.
If there are any girls participating I pity them.
Lor' Mum once told me an anecdote about her ebst friend. One day she didn't have any clean bras, so she wore two school shirts and went off to school. But she forgot she had PE.
And it was cross-country.
As Mum's Best Friend is . . . well-endowed there was much bouncing.
To quote mum's actual words (minus the swears): "It was bloody hilarious! Nearly wet myself laughing seeing [her] boobs bouncing up and down so hard she nearly knocked herself out!"

Bouncy castles will be problematic for everyone though.

@Spiryt: I think 'zira was talking about . . . shrinkage.