I love these ridiculous "let me wash your back" situations. Like, without fail, this will always lead to sex. It's like asking someone if they wanna get some coffee back at your place, but instead of coffee you're both already naked and no one can hear you cum in the deep space dimension of "the bathroom". Find me a doujin where LMWYB doesn't lead to sex, you can't and won't.

I did not know "bad" hot water was a thing... (Dirty/toxic water notwithstanding.)