Ianto holds back a comment on how they are obviously from different places, what with their accents and all. There's a difference between being deliberately obtuse and being deliberately cruel.

He forces himself to take in a breath before turning towards the other man, intending to offer something of an answer in return.

"It's --" is about as far as he gets before John's white-knuckling the counter and Ianto is all but leaping up from his seat, frankly rather alarmed at the sudden change in demeanor in the other man. "Whoa! Hey! You all right?" If John's about to pass out on him or something, he'd like to prepare himself. He sets his drink down warily just in case.