Oh. He had a very strong suspicion that he and Jack had learned it from the same person. He felt suddenly irrationally angry with the Doctor of Jack's universe, but he shoved it down so he wouldn't betray it in his body language. Jack might think the anger was aimed at him. Or that is was jealousy. Well, maybe there just a touch of complicated jealousy in there. Mostly he wanted to punch Jack's Doctor for being an idiot.
"Thank you," he murmured. "It wasn't my intention to upset you."
"Now," he said more lightly, moving his hands back up to the lapels of Jack's coat, and grasping them, "we don't have to do anything else, if you're not up for it. But I want to get you out of enough clothes to feel you up a bit. Sound good?"