Give Natalie "A Hand"

With Natalie's squirming lips held in one fist, Aaron was struck with a terrible idea.

He opened his fist just long enough to pinch down with his fingers to keep Natalie quiet, holding her mouth away from him to see a flat expanse of skin on the back.

Heart racing, Aaron lowered the back of his sister's mouth to the open palm of his spare hand.

An electric thrill ran up his arm, and he realised that he could feel the flesh in his wrist opening up to accommodate some kind of tunnel burrowing along his arm. It stopped at the elbow, and Aaron cautiously relaxed his grip on the lips.

The sensation of the mouth drawing breath was his only warning, and he clapped his hands together tightly to block the scream. Instead, a furious, muffled squealing could be heard between his hands.

This was too freaky, and as he was trying to think of what to do next he realised that the arm Natalie's mouth was attached to was actually trying to break free from his other hand - Natalie had somehow taken control of his arm!