Doctor and Jyn
Keen eyes spotted what Jyn had done, but instead of disapproving, the Doctor forced himself to swallow a smile as he exchanged a conspiring glance with her. He then casually looked around, noticing where the shop keeper was standing, as well as for other people that might be around to see.
Then, with the ridiculous ease, the Doctor nimbly swiped the paper knife's twin from the same area, but instead of pocketing it himself, he slid it smoothly into Jyn's pocket before strolling away to a fruit stall, two vendors away.
Thievery? Why not? After all, the Doctor began his adventures by stealing a TARDIS. And the young woman didn't look like the devious sort. The Doctor assumed that she might be hard up for money, and needed to steal to survive.
In fact, once he reached the fruit stall, he turned around and asked her directly, "Are you hungry?", while lifting up an apple.