Originally Posted by shinta
The very idea of making a joke right there is from emotion. He felt mischievous and did so. There was absolutely no necessity to do that. A totally emotionless creature would only do necessary things. What is "appropriate" to say is dependent on personality, which is rooted in emotions. Teasing Mayumi, and increasing her love points, is something that even contradicts his supposed existent affection for Miyuki. She would probably freeze the whole school if she ever learned about that joke.