Where there is a flame someone's bound to get burned

Remus and Tonks knew there was a chance that Teddy was a werewolf but after his first full moon and no transformation they believed he wasn't and died believing that. But Teddy was not just a metamorphosis, he first transformed when he was five, and now is scared that anyone near him will get hurt.

Or Teddy's teenage years as he navigates being a werewolf and being scared of hurting people.