"I'm not being thick! There are different kinds of rings-- and I don't always flirt, either!" It's his turn to roll his eyes, but he also holds out his left hand to better let the Doctor see. "Yes, we're wearing matching ones."
He holds Ianto a bit closer, instinctively turning his head to press a kiss into Ianto's hair as well.
He has to laugh when Rose just has to think of chips almost first thing. "Ianto, what's the best close-by place for chips? Oi, Rose, looks like you've got one of the good-looking ones plenty taken yourself."