Something Between Us by D.T. Brandt
Raith is an Ichthien, a water-dwelling species that wears a mask on shore to protect the humans that live there from falling victim to their coercive siren-like voices. He has a crush on Cam, a human who works at the forge where Raith delivers carts of oreballs dredged from the lake floor. Once they finally meet cute and start spending time together, Raith begins to fall prey to the expectations of others and the constraints of their separate worlds. Meanwhile, Raith's sister Kiela is trying to uncover a secret about the Ichthiens' past that he doesn't think even exists. As her research chips away at his doubts it also uncovers a possible path forward with Cam, but at a steep cost that Raith must be certain he's willing to pay.