After Gloria's wish, a brilliant green light blinded the room. Bill stood for what seemed for an eternity before the light faded away.
When Bill's eyesight returned, he instantly recognized the place where he stood: His house! As in his house from 2018, not his weird but still really cool future house. Looking down at himself, he found that he was back in the same teenage body he started this day with, Same teenage clothes, same teenage build. Looking up again, he saw Gloria, same as she ever was, except a few moments ago when she was older. But as Bill looked around, he started to see that not everything was back to normal.
First of all, there was Tammy, who had not returned to his Tom form, but was now simply a teenage version of Tammy. She was slightly chubby, not as heavily built as the older version. Her blonde hair flowed downward, and she was wearing a Black Widow Shirt and jeans. Bill couldn't help but to find himself incredibly attracted to Tammy. He wasn't sure if this was a residual effect of the magic or if Tammy truly just was his ideal woman. But he couldn't stop thinking about how much he wanted to kiss Tammy again.
But then Bill's eyes turned to the other elephant in the room: Willow! She was still rather stylish, wearing a nice red dress and black heels. Bill couldn't help but to wonder what was going through Willow's mind right now. Bill, Gloria, and Tammy obviously knew about this weird stone. But Willow had been a construct of an alternate reality. Does she remember her past? Or has the stone adjusted reality once again?
Option 1: Willow freaks out about her parents being teenagers and being stuck in 2018. Bill and Tammy try to explain, but Willow grabs the stone in a panic.
Option 2: Willow believes she is Bill's sister, at which point Bill realizes that the stone has made more strange changes to reality that he didn't suspect.