The Doctor grinned against Jack's mouth. This, this was good. This was what they needed, the two of them. Far too often, things got so muddled or confused, they were never on the right wavelength. This was good. This was right.

He broke the kiss and pressed his mouth to Jack's jaw. He could taste the water from the ocean, along with some sweat, and some of Jack's pheromone. If he were scientifically minded (which, as a matter of fact, he was), he might go so far as to try to determine the pH in Jack's body from the taste.

Of course, he couldn't get too caught up in the details. Thoroughness was, after all, an important part of any experiment.