- Totally Spies!: "what if... the girls remained young" (Episode I Hate The Eighties) [given by wildfire377 from AO3]
it was the following morning after returning back to their normal ages that the girls woke up and gave out screams, they had turned into kids once more, they called up Jerry who Whooped them as soon as he was told, he preformed many tests and informed them that some odd energy had mixed with the de-aging energy of the 80fier resulting in them regressing into children, Sam says it must have been the time energy from when they where sent to the future, the girls get upset thinking they have to grow up again and then suddenly they return to their normal ages.
after some more tests Jerry has them each think of when they where young and when they do they de-aged back to children, thinking about being older returned them to their teen ages, he went on to explain that not only could they change between ages but it seemed their aging had greatly slowed down, by the time they became 40 they would look 20, this had slight mixed reactions from the girls, happy they would retain their looks and spy careers for many years, but sad knowing they wont be able to settle down with someone without drawing questions about their slow aging.
as time passed the girls became the best agents in Whoop, especially with their child forms that allowed them to sneak around villains without them noticing, and as time pass they grew closer as more than best friends, filling the emptiness with each other.