To hide his booty.
Show me your booty.
He kept trying to plunder her booty.
Aaahhh.
Arrrh, it's driving me nuts
Last years hide and seek champion
Fowl play !
Stripey pyjamas !
If she's only wearing one sock. (This joke brought to you courtesy the homeless guy outside my local 7-11.) Edit: tweaked the punchline.