Tamaki was perfectly aware of Kyoya's dark side. After all, he had provoked his quiet classmate into showing his true self to him. The trouble was that, with the situation in front of him, Tamaki was realizing that he didn't know what Kyoya was fully capable of in one of his dark moods.
Kyoya had agreed with him that Haruhi had been careless with her own safety. He had seen the anger simmering in the depths behind the glasses as Kyoya's security team had evicted the two troublemakers, though Kyoya had calmed by dinnertime. But had Kyoya…? The megane seemed bored, standing there with a towel hanging around his neck. The rest of the scene was…strange.
To start with, the lights were off. Since Kyoya was wearing a tailored pair of pants, he obviously wasn't planning to sleep. Tamaki also knew that it was far too early to find Kyoya planning to go to sleep; it was still a good time to visit his room.
Secondly, Haruhi was sitting on the bed. Seeing her was surprise enough, but if Kyoya had asked to speak with her, wouldn't he have used a quiet corner in a more public setting? Why in his room? Why weren't both of them sitting at the little table in front of the windows?
Last was the bed itself. When Tamaki had glanced in earlier, it had been neatly turned down, waiting for an occupant, not any different from any other bedrooms they were using. Now it looked rumpled, and the top sheet was tossed to one side with the blanket. Haruhi's eyes were wide and her hair seemed a bit tousled, but Kyoya was perfectly calm, tossing the towel onto a chair and picking up a shirt.
For some reason, the movement incited a burst of anger and trepidation. "Kyoya…"
"You wanted lotion, right?" The black-haired man pushed a bottle against Tamaki's chest, walked out of the room, and shut the door behind him. What made Tamaki worry was how Kyoya didn't look him in the eye.
I could have misinterpreted the tone of that one word in the English dub, but it's an interesting thought, hm?