"Howzabout I could use the balloon to shrink you?" Jim asked his dad. "OK." Ron said. He gave his son the inflated balloon. "Control my dad's size," Jim said.
He let his grip on the balloon slip ever so slightly. A light hiss escaped.
Ron shrank.
He held the balloon shut again. It was only a few inches of height lost, but his dad could feel his clothes were noticeably looser on him. He could tell that the room around him was almost imperceptibly larger. He chuckled. It was working. He wanted more. He let out more air.
That shrinking feeling was intoxicating. His whole body seemed to exhale in a sigh of relief. He stopped the hiss again. This time, Ron was the same size as his son. He giggled. This was amazing! He felt his pants drop to his ankles taking his underwear with them. His shirt hung off him like a dress, covering him almost to his knees. He stepped outta his huge shoes and socks.
Jim loosened his grip on the balloon again, this time letting out more air than before. Ron could feel himself dropping down, like riding a high-speed elevator. He felt a thrill-ride drop in his stomach. His too large shirt slipped off his shoulder. He realized that he no longer wore it as much as stood inside it. The world expanded all around him. The furniture grew like living buildings in time lapse. He was grinning ear to ear.
Soon, Ron was doll sized. And he was naked.