So -
Baby balloon is in bed with her parents, Daddy and Mummy Balloon (oddly enough)...
Daddy balloon says "Baby Balloon, you are getting too old for this..you are 3 and half now. Tomorrow I want you to sleep in your own bed."
"Aww..ok" she says.
"You promise?"
"Yes"
"good girl".
Next morning, early, Baby sneaks into the parents' room. She unties her mum's knot and lets a wee bit of air out and then reties it. She does the same with her dad.Finally, she unties her own knot, lets out a wee bit of air and reties it. She softly sneaks in between them and goes to sleep with a big smile on her squeaky face.
Next morning, her parents are less than amused at her behaviour despite her promise.
Daddy balloon says "I am so disappointed in you! Firstly, you let your mother down. Then you let me down, but..worst of all..you let yourself down!"
sorry - i like it!