Chapter 18, I think, and 19:16 on episode 9.
-.-
The light was reflecting off his glasses. Not a good sign. The fact that Kyouya was twitching violently, simply staring at the letter in his hands, was also a bad sign. "That little... I'll hunt her down and make her pay," he hissed furiously. Hunny blinked at him.
"Kyou-chan? What's wrong?"
The dark-haired teen's usual composure was lost as he spluttered in fury. "How dare she?!"
Tamaki snatched the paper from him and started reading it aloud.
"Dear Kyouya,
"You know, you're my favorite character. Admittedly, you tied with Mori and Hunny, but still. You're just so deliciously sexy, and even with your glasses on I swoon when I see you. Then, that one episode where they showed you in bed? I swear, I was squealing the first time I saw it (and the second, and the third, and...). However, I wrote this letter for a reason other than complimenting you.
"You look very pretty in a dress. That anime episode with the Lobelia girls, I ended up watching... well, a lot of times. And that manga chapter, with the Alice in Wonderland theme, it was glorious. So perfectly you. The Dark Queen! Honestly, I wish I looked that good in a dress...
"Anyway, keep up the utter hotness!
"A devoted fangirl."
P.S. I am now giggling at imagined hints of Mori/Kyouya.
P.P.S. Hunny, you looked cute too. Someday I hope to rock as much as you do.
When he finished there was dead silence. Then the twins burst out laughing. Mori looked at Kyouya with an almost speculative gleam in his dark eyes, while Hunny cheerfully congratulated him on his... success and Tamaki was his usual dramatic self, utterly joyous as he proclaimed that he would do his best to ensure that this loyal fan was satisfied with even more crossdressing!Kyouya.
Kyouya snapped. "I WILL KILL ALL OF YOU!"
-.-
Seriously, he is so cute. Especially with that "I will murder you all" look on his face.