kid
handle (or treat) someone or something with kid gloves deal with someone or something very gently or tactfully.
☞ Kid gloves are those made with fine soft leather from a young goat's skin.
kids' stuff something that is childishly simple or naive. informal
1982Vivien AlcockThe Sylvia Game He had grown out of the game; it was kid's stuff. Besides it always landed him in trouble.
a new kid on the block: seeblock.
our kid your younger brother or sister (often used as a form of address). British informal