There’s a lot of mermaid Connor out there. But have you considered this:
Mermaid Hank.
Connor and Nines like to spend the weekends floating in a boat, allegedly fishing but actually just escaping from the world at large. There’s stories about avoiding a section of the sea because of sirens tempting sailors to their death but they think it’s actually just a hidden sandbank that strands ships.
They skirt around it usually, until they both accidentally fall asleep in the warmth of the sun and the wind carries them to the forbidden patch.
In reality, it’s avoided because ships sink there for no reason. There are no sandbanks, no hidden rocks. But the sea floor is littered with sunken wrecks. It’s the tipping of the boat that wakes Connor and Nines. They peer over the side of the boat with curiosity and worry. Connor falls flat on his back when a grouchy face peers up at him from the water.
The sea is home to a clan of mer-people. Hank is usually the one to chase off intruders from their territory and uses whatever means he deems necessary. Since he got an apprentice (Gavin), those means have turned a little less friendly and a lot more destructive. It’s a fun way to let loose any built up frustrations, plus any wreckage brings more hiding places and living spaces for the mer-people.
Together, Hank and Gavin had been prepared to wreck the intruding boat without much consideration for its passengers.But seeing the two, near identical, faces gave him pause for thought. Then Hank’s pet octopus decided it wanted to make friends. Oddly, Gavin had been pretty quiet about the whole encounter which Hank finds off. Until he looks over to see Gavin is transfixed on the other human, eyes wide and tail curling in a subconscious mating display. Hank would laugh except he realises he was doing no different.
Anyway. Long and short of it: mermaid Hank.