Big Sis drops a teddy bear on your lap! It's... hollow, and floppy. Wait, of COURSE it is, that's the costume! Except it's got no zipper, only a big hole in the back, and it's barely half your size. Is this what it means when grown-ups buy something for "half-off"? Wait, no, of course that's not what it means. The real grownup trapped somewhere deep inside Kim feels embarrassment at even thinking that, and you blush.
"HHY OOH EEH EHT." You stick a hand inside the teddy bear's stumpy arm. The costume (if it really is one) is nothing more than an empty shell with some padding on the paws. You barely fit in there past your wrist, what gives?
Big Sis pulls your arm out of there. "Nah, not yet. There's some other parts." She starts wrenching your elbow, and you scoot away from her with a grunt. "C'mon, Kim, this is the only way you'll fit. You'll get to hold the candy too, okay?" The promise of getting to control the candy has you convinced, and you relax. One by one, your wrists are bound to their forearms by plain leather sleeves with heavy, buckled straps. You feel panic setting in as you strain against the bindings, but Big Sis pokes you in the stomach. "Stop that, you'll be fine, I'll be right here doing my tasks with you. You're my task." With the clanking of brass buckles, she inflicts the same bindings on both of your legs, tying your ankles to your thighs. In only a few minutes, you've turned into a wiggling chicken nugget in a diaper. Somehow you feel this could still be worse.
The empty bear skin flops in front of you as you lean forward. "Just jump right in," says your Big Sis. Your crawl in- there's no word to describe walking on your knees and elbows other than crawling- and let the older kid pull your limbs into their tiny slots. What do you know, now you're a perfect fit. Thanks to the thick layer of padding, your diaper is hidden from the world, and even the pacifier is behind the glassy eyes of your mask. Maybe this won't be so bad.
And then you feel it... a tugging at the back of your costume as it slowly gets tighter and tighter, warmer and warmer. It seals up entirely, followed by the sharp snip of a pair of scissors. Big Sis walks in front of you... with a sewing needle. It's official, you're stuck in this thing until she wants to let you out.
"Let's go, Kim." With zero fanfare, she lifts you like a sack of potatoes and buckles you into your old baby stroller. You're left waggling your limbs uselessly as she rests the candy bucket between your plushie "paws". Whatever happens next, at least your identity is safe behind the costume...