It's been six months since I've walked on two legs, six months since I've spoken more than a handful of words at a time, six months since I became a werewolf. Or at least, a pretend werewolf.

My little sister, Lily, performed some birthday magic and turned me from a 16-year-old teenager into a 4-year-old toddler. She wanted someone to trick-or-treat with, and I, always the dutiful big brother, agreed.

I loved it. The simplicity of being a child again, of being a werewolf, of being Lily's favorite person. I growled, I prowled, I bit anyone who tried to remove my costume. Except Lily, of course.

Today, things are different. Mum and Dad are going out for the night, leaving Lily and me with a babysitter. But not just any babysitter. My ex-girlfriend, Emily.

I can't bear the thought of Emily seeing me as a toddler, as a pretend werewolf. So, I do something I've never done before; I take off my costume.

Lily looks at me, surprise etched on her face. She knows how much I love being a werewolf. But she doesn't say anything. She just watches as I put on normal clothes.

Emily arrives and I can tell she's surprised. Maybe she expected to see me in my werewolf costume, or maybe she didn't expect me to look so...normal.

The night is awkward. Emily tries to talk to me, but it's hard for me to respond with more than a few words. I'm not used to it. I miss being a werewolf.

Bedtime comes and I can't help but feel a pang of guilt. I've been acting more human tonight, and I can tell Lily's worried. She thinks I don't want to be a werewolf anymore.

I crawl into bed with Lily and she looks at me with wide eyes. "You're not a werewolf anymore?" she asks, her voice small and worried.

"I'm sorry, Lily," I say. "I didn't mean to scare you. I just...I didn't want Emily to see me like that."

She looks at me, her green eyes full of understanding. "It's okay, Jack," she says. "I know you're still my big brother, even if you're not a werewolf."

I hug her tight, grateful for her understanding. "I love being your big brother, Lily. And I love being a werewolf. I just...I guess I got scared."

"It's okay to be scared," she says. "But you don't have to be. You're the best werewolf and the best big brother."

Her words warm my heart. "Thank you, Lily," I say. "I promise, I'll always be your big brother. And your werewolf."

She smiles and hugs me back. "I know, Jack. I know."