The Doctor's mouth quirked slightly at her reaction. But he answered as if he didn't notice her sudden suspicion while following her. He spoke calmly. His long strides caught her up rather quickly
"I'm exploring, can't stop really. Did you go to all four floors of cabins? There are up to four-bedrooms per suite and I considered if I should choose one of those. Maybe I'll change my mind."
Though it might be best not to. If the Doctor happened to 'borrow' some things so he could study them, it made more sense to be in a more private room so he wouldn't be interrupted.
They reached the mess hall. With a glance at the soldier, he strode forward to walk in front of one of the food counters. This one had pictures of food people from the British Isles would be familiar with: fish and chips, just chips sans the fish, crisps, a breakfast plate including baked beans and another featuring smoked kippers, even haggis and jellied eels, and others as well as tea. The Doctor looked at Shepard again to see what she was doing. He stopped moving around.