"Cousin Finn!"

The script writers sometimes make me cringe. Never once have I referred to one of my cousins as "Cousin Name". I understand the "Aunt" and "Uncle" but never "Cousin" first.

Edit: I understand why they've done it, to reiterate the fact that Luna doesn't know and their previous relationship was cousins. But holy heck surely there has to be other ways to get that message across.