"You can write me a whole letter of complaint if that's what you want."

He takes Ianto's t-shirt off him and slings it over his shoulder on top of the other one, squirts some of the sunscreen into his hand and hands off the bottle to Ianto before beginning to quickly work it over his shoulders.

"Trust me as the person who's been to more hot countries, alright? I'm not doing this just to try and make you uncomfortable."

Since he can tell Ianto is uncomfortable, which isn't terribly surprising. He never came across particularly confident in his own body. John can try and move quickly so it isn't lengthy torture.