#kailor

They would start officially dating in Season 9, Hunted. This time period is where the original four are in the never realm, and Lloyd is stuck in Ninjago along with Canon Nya as his support, so Kai in the SWAP AU. (And pixal with Dareth). As Skylor later on joins with the other elemental masters, this would give the two of them time and vibe to get to know each other even better. In the end they officially date lmao

As for nicknames...that was a hard one tbh. They don't look the type to call each other sweet things or petnames like baby or honey to me, but maybe teasing ones from Skylor especially, or when she makes fun of him. So maybe some like "Splashshot" instead of the Canon "hotshot", then there might also be "Waterboy" (not sure if she called him fireboy in Canon, I dont remember) and "Wavehead" when calling him stupid

From Kai's side, the most simple one would be "Sky". Literally just a shorter version of her name, but if going on flirting way, definitely stuff like "beautiful" and "gorgeous". Sometimes when he feels like it, "copycat" when teasing her element (she did NOT like that lmao)