Donna reached for the tube of Colgate toothpaste in her bathroom vanity , half asleep, she fumbled around, but the tube wasn't on the shelf where it was supposed to be. She groaned, instead, she followed the corridors of the TARDIS, to the place where she would know it went to.
She knocked on the Doctors bathroom door, she could hear him brush his teeth. He mumbled to her through his toothpaste to come in, and she found him, indeed at the sink, brushing his teeth with a blue toothpaste, the missing tube of Colgate toothpaste on the vanity.
' OI SPACEMAN ! BUY YOUR OWN TOOTHPASTE IN FUTURE , AND DON'T USE MINE!' she bellowed. The Doctor didn't say anything, just grinned at Donna, with a toothpaste filled mouth. He rinsed his mouth, and grinned again at Donna's reflection, hands on hips in the doorway.
' Sharing is caring' he told Donna , who still had a look of annoyance on her face.