Vampire "Coming out" Scene

So In my story, the two main characters are a human girl, and a boy who is a supernatural creature similar to a vampire (I don't want to say exactly what because I get to paranoid."
Anywyas, How do I go about writing the specific scene in which the MMC tells the FMC about himself being a supernatural creature. I've only spent a page on it, and I feel like the scene needs to be longer, and more important, please help

Hm...I'd guess it's a lot like telling your folks something you're really excited about but you know they'll hate. It's not a topic that will be settled in one conversation, so you could stretch out the timeline.
"Hey mom, a concert promoter heard our band and offered us a contract. We're going on the road in a week."
"Your only 15. You haven't even finished high school."
"Yeah, um, well- I'll be dropping out. But-"
"WHAT!"
Conversation goes on for a page or so..and of course, mom is not happy. MC must now spend some time in room, trying to figure out a new tack.
After dinner and the dishes, when MC hears dad safely ensconced in front of the living room t.v., MC sneaks back into the kitchen.
"Mom, can we talk?"
(and here, the discussion continues in a more heartfelt manner. ...only, with vampire-esque creature.

First, I guess that if your vamp-char wants to be taken seriously he has to build a lot of confidence with the muggle. Without that, I don't think the actual conversation would have sense - A:"You know sweety, I eat human souls." B:"Yeah, right Jake, go play Wii..."
Then, he needs some kind of strong motivation to "come out of the closet/coffin". Simple need to progress their relationship is far from being enough. If you ask 99% of us muggles what we seek most in relationships the answer would be "sincerity, sincerity, sincerity" - but still, 99% of relationship fall apart from the LACK of sincerity. Now, with that fact in mind, your vampie is good enough pretending his mugglegirl is just fine living "in the lie". You know - "Why can't you accept me for what I am in real life, forget about this flesh&soul-devouring monster I become every now and then."
Third, decide what kind of character he is. I knew a couple of would-be LBGTs who "came out of the closet" for simple adolescent disobedience - just to piss off their parents. I guess in a vamp-friendly culture (like nowadays western culture) there would occasionally be people "confessing" their "vampirity", without ever tasting human blood. As there are people getting aroused thinking of blood-sucking monsters. So, is there a personal, selfish reason behind his confession? Or he just feels confident in the muggle? Does the confession mean something more to him, maybe in context of social acceptance, child traumas, etc.?