you're a Mer pup, after being rejected by your own pod and left to die a Siren named Phil takes you in, despite the unease of the Siren pod and the decade long hate between Sirens and Mermaids nobody dares to defy Phil being the oldest and biggest one in the pod so you're allowed to stay

Stay close

Phil coos at you, but slows down slightly to allow you to catch up, you swim just beneath him hidden by his side fin just like the other pups of the pod