Kaiyanese
A made-up language only Kaiyas can understand. It's like a secret code that only they know, and everyone else thinks it's nonsense.
Kaiya: "Zoqra puxi vella." Me: "What?" Kaiya: "You're just stupid."
Kaiya texts: "Florp zorp nox." I reply: "What?" She replies: "You're a doofus."
Kaiya says: "Klempa zorp." I say: "That's not a word." She says: "It is to you."