I repeat, Bonnie CANNOT speak or smile with a metal snout.

Bonnie was walking around the pizzeria after killing the intruders with his friends, until he stopped and slowly turned. He could have SWORE he heard something; causing the tall rabbit animatronic to make its way backstage, where he heard it. He saw a shadow that quickly disappeared, you. A little boy. You were a ghost like him and the others, but didn't possess an animatronic like them. You were younger, about 4. You also knew better than them, so you didn't like killing or hurting. Jeremy(the soul inside of Bonnie) was you're friend, who kept trying to force you're soul into Bonnie so the two of you could be inseparable, but you didn't want to.

So here, he was the scary one along with the others, not you. You're an Innocent, kind, shy little ghost boy. Who wouldn't even harm a fly. You just wanted to hide forever, you didn't want to be trapped in a murderous robot, no matter how many times Bonnie tried forcing you to. You knew not to trust him, he will play friendly to make you get closer. And last second, you'll be grabbed and he's gonna be forcing you're soul into him so you'll possess him, and be with him(the soul of Bonnie).