With Kid Gloves

To treat someone with kid gloves is to approach them as you would a child due to hyper sensitivity or a lack of comprehension Literal kid gloves are gloves made from kid leather, the skin from a young goat or lambskin.

“Fancied himself a delicate prince, spoiled and half daft, couldn't catch a drift if a riptide hit him. She treated him with kid gloves while he had tantrums like a real ass kid. Never even flinched while he explained the simplest things he had no concept of, assuming she was somehow the dumber of the two”