[That absolutely sounds like something he shouldn't pry about-- so while he definitely hears it, he's just going to pretend he didn't. It feels like the best way to handle it.]

I'm afraid I don't know of any... if it's just stained, it might fade, b-but if it's permanent... you might have to keep covering it.

[But, hm. There's another thought from him too as he lifts a hand, fingertips lightly brushing over his chest- that burning feeling earlier, was it also...?- before he just fidgets idly with the fabric of his shirt instead.]