"Maybe next time," Jack said comfortably, because while he was very glad she'd got other people here that she knew, he was enjoying this being just the two of them right now. He'd always had a bit of a thing for Martha but - as with Gwen back home - he was too much of a gentleman to try and take advantage while she was already in an exclusive relationship.
Which, while he was aware there was *something* about Tom going on, he assumed she still was. She'd made it pretty clear she didn't want to talk about whatever it was, though, so he'd respect that, for now.
He grinned at the UNIT stuff. "It's like you're the Doctor's spy on the inside. Infiltrating UNIT even now to use them for his purposes. You should've seen them back in the seventies when he was stranded on Earth and they were all forced to work together!"