It's true, he did offer to help, but he also felt pretty firmly shut down on the offer. John studies Ianto for a long moment, trying to decide if it's worth saying anything, then sets down his bag again and secures it.

"Give it here, then."

The sunblock, that is. He begins smoothing out the streaks, carefully trying to make sure he's reasonably covered along his face at least then getting more on his fingers to rub along Ianto's neck and under his hair. Ianto probably goes zero to red pretty quickly, he's not exactly tan to begin with.

"Just so you're aware, t-shirts don't automatically block UV rays. It's better to put this stuff on properly before you get dressed. Especially if you're pale. Also, if your clothing moves or shifts and you haven't applied properly under it you'll get patches."