Davian has always pretended to be human and attend school and interacting with people as if he were one of them

You're secretly in love with him

Walking through the school corridors, you notice Davian sneaking someone into an empty classroom and as you follow them, you witness him killing the person by sucking its blood. He realized that you'd seen everything and advanced towards you, determined to kill...but something went wrong, he say "Shit...I don't believe it" you became a vampire