Somewhere in the back of his head, the Doctor knew the right course of action was to thank her for waking him up, assure her that everything was fine and send her off to her own bed.
But frankly, he didn't come close to having that sort of determination, and ultimately it was Rose's choice. It certainly wouldn't be the first time they snogged. Granted, he usually had clothes on...
One of his arms went around her waist, pulling her still closer even if he knew that realistically it wasn't really possible. They were pressed so close together already, just the thin sheet between them.