That's not how you're supposed to use medicine! That's a dangerous amount of medicine they're rubbing into themselves!
I’m not terribly knowledgeable about Japanese pharmaceutics, but considering they were able to pick up the “medicine” on their way home, I doubt it was anything too extreme. At most it was probably an over-the-counter anti-bacterial cream, and at least it was just some fancy body cream. Overuse probably poses a bigger threat to their wallets than it does to their health.
Anyways, speaking as someone who has had to deal with chafed nipples before, I was definitely wincing once things started heating up. Just, oof.
Was still really good, though.
