I was kinda surprised by Meruru. Apparently Kirino's favorite anime is an extra-violent version of Nanoha
. And a Nanoha where the girl doesn't just sadly beat a girl's brains out to force her to listen to reason, she actually grins and incinerates her best friend! At least Nanoha never killed someone she liked, and seemed to dislike hurting them. Cute though it was, I'd probably be very disturbed to see any girl singing along with that, especially with Kuroneko's commentary on what the lyrics actually say.
Seriously, Kirino was walking dangerous ground at the hotel. It was a good idea, and a necessity since she'd just deliberately drenched herself in cold water in December, but still... And even if Kyousuke didn't think anything of Kirino in a bathrobe, he'd still get nervous to have a girl hear his little sister talking about the bath in a HOTEL. And since it's clearly that sort of hotel, you can't blame the guy for thinking on those lines. I mean, it's not even a makeout point or some place that'd been designated for the purpose, this place was built and run for people to pay and have sex. How can you not think of it in a place like that? Only thing would have been better is if he'd jumped at the sight of her and accidentally turned on the TV...