Karyn the blow up doll

Karyn felt her skin stiffen as the change happened. Her arms went out from her sides and her legs spread open. "Why me," she thought as she blacked out.
Jon fell onto his bed laughing so much that he nearly cried.
"I wish she knew what was happening" he said, and Karyn's sightless eyes focused onto the ceiling. The sound of Jon laughing annoyed her. "Change me back" she tried to say but no sound came from her latex lips. "Not yet" said Jon "this is just too funny. It is a pity that you can't see it. Perhaps I ought to try it on Sarah next"
"Pervert" was all Karyn could think to that suggestion.
Then Jon heard his mother at the bottom of the stairs. "Jon your meal is ready. Has Karyn gone home?" Her footsteps could be heard on the stairs.
Jon had a moment of panic. What should he do he wondered, as he looked at the doll and then at his bedroom door.
Then it came to him. He quickly put his hand into the back of Karyn's clothes and hunted for the air release valve. " I never thought I would be doing this to you " thought Jon
"Rape, rape" Karyn cried, but gave up when she remembered that no-one could hear her.
Jon quickly let the air out of Karyn, took off her shoes and proceeded to roll her into a neat bundle, all the time letting the air out. Just in time he was able to put her and her shoes into his cupboard and closed the door. Once again the world went dark on Karen again.
"That's odd," said Jon's mum as she came into his room, "I didn't hear Karyn go out."