I get it. But there's a thick line between what you did - protecting your kid from a danger he was helpless to deal with himself - and what Grandma did - signaling to the kid that there's something wrong with his curiosity and playfulness. So long as the daycare didn't hold him down and paint his nails by force, there's nothing in this story to indicate grooming. Odds are, he had a blast doing that with his friends. Not good to stifle that sort of thing.