Cough it up," she tilted her head back, speaking to the TARDIS around her, smug as could be - even with her barely towel-dried hair sticking to her neck and naked shoulders. Rose Tyler marched, naked, to her bed and opened up her drawer, happy to find a ten-pound note, un-creased and unmarred, sitting in it. She pulled it out and fanned the air around her burning cheeks with it. You see, when you travel in space for long enough, you begin to find ways to amuse yourself aboard whatever your chosen vessel may be. When that vessel was a slightly cheeky, conscious being with a leaning toward femininity and immaturity, those ways of avoiding boredom tend to be slightly mischievous.