Suki ni Nattara Dame desu ka?

After Kaname jokingly called out to his teacher Natori about him ogling male students, Natori was so shaken up he couldn't teach properly. Later when Kaname was called into Natori's office, Kaname confessed that he himself is gay and that Natori doesn't need to worry about rumors. Even though Kaname has no intention to blackmail Natori, he decided that he'll spend his time teasing Natori.

(Source: MU)