"On your twentieth birthday, I'll have sex with you!"
Heat rises to Tails' cheeks, and his tails twist around in a sort of cringey terror.
"That's a bad word," he whispers to Amy.
They are respectively six and five years old. Neither of them actually really knows what sex really means, except Amy does, it's what she's going to do with Tails when he is twenty. They are at a birthday party. It's not Amy's, or even Tails', but Sonic's.
"Maurice!" Sonic's mother's voice explodes from the kitchen, and Tails puts his hands to Amy's mouth, so that she won't say the bad word again for the adults to hear. If the adults know what they are saying, they might get mad.
"Cake! Cake!" Sonic only yells joyfully as he looks up from the cherry oak table, his blue-quilled cheeks lit up by the glow of the candles on the cake in front of him.
"Maurice!" the voice yells again. "Maurice?"
When he hears that voice, Tails can feel his fur stand on end, despite himself. Sonic is still staring at the cake. "Cake, cake!" the child repeats.
Beside him, Amy's giggles get louder and louder, and it makes Tails nervous. What if they hear… what if they get mad at him…?
Well, no one actually hears what's he's hearing because there's no Amy, no Sonic and no birthday party at all. Tails doesn't exist either; Tails is just the identity you've invented for yourself, in order to brave the unbearable. Strapped onto a metal bed in the isolation room, burly nurses come inject you with medication to make the voices stop.
Alas, sadly for you, they don't.