Feeling silly is fun!
Sometimes parents join in and celebrate by tossing out playful names like: "You silly goose!" This is all in good fun, but in the interest of emotional safety (and the HUGE benefits of said safety) perhaps it would be better to celebrate without any labels. This makes it clear that not even subtle playful judgement is placed on feelings, that all are ok and none define who you are.
Instead: "You feeling silly?! WOO HOOOO!!!"
Image credit: Feeleez Matching Game