At least they call your kits toys.
Try having people calling 1/6 military action figures, dolls.

That's why you have to clean your own room instead of letting your mum clean it

If you really want to replace the V-fin, try finding a 1/100 Bendi and use it as a spare
Same as my dad's reaction when I showed him the skeleton and sliding pistons of my MG MKII. He actually thought that Gundams are like remote controlled cars when we can control its movement or make it transform on its own.