The tiny naked Jim jumped outta the shoe, and ran out from under the bed, WHERE HIS GIANT FATHER WAS SITTING.
"Hey, dad!" he yelled! " DAD! I'm down here!"
It just so happened that Ron happened to notice a doll that resembled his son, only realizing that is WAS his son.
"Son?!" Ron exclaimed, in a voice that made his son wince and cover his ears. "What happened to you?!"
ONE EXPLANATION LATER....
"So let me get this straight." Ron said. "This balloon allows you to magically change human bodies." Jim nodded. "And you want me to try and make you bigger." Ron said. Jim nodded.
"Ok." Ron said. "Read me the instructions."
"OK." Jim said. "For growth, say the spell you want, then inflate the balloon."
"OK." Ron said. "Control my son's size." He then took a deep breath, blew into the balloon and it expanded with a “FFOOOOOFFF” and the sound of stretching rubber. At the same time, Jim grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew and grew till he was normal sized again. he quickly put his clothing back on again.
"So," Ron asked his son, "What shall we do now?"