I have a touring bag that I keep all essentials in and don't take out for any other use, so I never forget the main things.
I'd just answer with a towel like mentioned above.
Personally I wouldn't conceal the burn with make up as probably looks worse or makes it look like a hicky - I'd just simply say I burnt it with a tong / I don't think a man will care.
Spots happen, don't worry about it