After settling on the surface, Sans and Alphys became lab buddies and they often brainstorm ideas together for miscellaneous projects… and the robots. Upon having different robots other than Mettaton, they decided that there must be a more efficient and “fun” way to clean them, externally.
The Space-Robot From Earth (Who Never Made It Onto A Flight Team And So He Works For The Public Relations Department And Spends All Of His Time On Earth, Mostly Visiting Schools and Raising Knowledge of Space Robots).
That’s actually a pretty smart vest that robot’s wearing. Vests look better on skinny people (but only because most things do), but I can imagine a future in which slick vests with pockets are a part of my outside-the-house-work-slash-school wardrobe. Inside the house wardrobe will continue to consist of sandals and underwear. And when there’s company I’ve invited, some shorts made for athletic activity that have never seen any athletic activity. When there’s company I didn’t invite, I put on a shirt under great duress.