Fuggly neighbours

"Woah!" the son exclaimed when he saw that the old neighbor, Mrs. Prust, was standing in front of him.
"And, did I promise you too much?" came from her, still in his father's male voice.
"Unbelievable Pa, that one of your crazy inventions actually works—Hey, what are you doing!?" exclaimed the son, seeing her just standing there!

"I'm just checking if everything is in place! Why?".
"Dad, yuck! Prust looks like a fat whale!" Peter said indignantly.
"Oh, you're right! I better transform back!" Walter said and reached for the invention.
And once again Fizz, he transforms back!
"Thank goodness! The fat whale is gone!".

"Son!" Walter exclaimed, referring to him.
"Oops, 'sorry'!".
"Peter, I just need to finish filing a report here. And afterwards..."