the bed was the canvas; we were the art.

‘Come on, Ginny’s not bad,’ said George fairly, sitting down next to Fred. ‘Actually, I dunno how she got so good, seeing how we never let her play with us.’ 'She’s been breaking into your broom shed in the garden since the age of six and taking each of your brooms out in turn when you weren’t looking,’ said Hermione from behind her tottering pile of Ancient Rune books. 'Oh,’ said George, looking mildly impressed. 'Well, that’d explain it.' 

Harry Potter and the Order of the Phoenix