The nabe pot has an aphrodisiac ingredient inside that is affecting the air. If you have the time look up the original golden kamuy chapter, it's hilarious.
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Oh, there goes the swimsuit again...Oh, this Demon King... She's just too damn lewd!My head is spinning...Are you okay, Ryouma!?You've got to lie down, right now!Let's loosen the clothes around his chest so he can be more comfortable!You should take off the clothes on his lower body, too.No... all of them! Take off all his clothes!