Key in Public
Hi Jonny - this isn't a key in a cylinder, it is the actual key. https://www.maturemetal.com/product/security-screw/
My wife loves to flaunt her key. If she is asked about it, she doesn't say directly what it is for, but replies with something vague like the "key to her marriage" or the "key of love."
She told her sister that it's her "power key" and when she's wearing it, then she has the power to decide when I "get some." But she's never told her overtly that it goes to my chastity cage.
We have an assortment of Master locks with various colors that she matches the key to her outfit and my lock to her key. She mostly wears the pink or black key, usually on a necklace, but sometimes on an anklet.
I don't find it unusual to wear a key as a piece of jewelry, you see that more often. A key can be a symbol for anything. Normally, only the wearer and people close to them know what it stands for.
My wife used to like carrying the key too. Not to pose any riddle to anyone, but simply because she felt comfortable knowing that the key to my heart and my sex dangled from her necklace.
She never wore that ugly standard cage key though. At that time she found a beautifully decorated tiny jewelry box at a flea market, with an equally tiny and beautiful key. The ugly cage key went in the box and the box key went on the necklace.
But she hasn't carried the key for a long time now.
I might have to remind her again...