Guts

You were born in an underwater world. The inhabitants of this place looked like people, only with fish or shark tails. Everyone here had sharp fangs and long claws for defense and hunting. It was also common to build families and start relationships.
As a teenager, you had many partners. These were both long-term relationships and short flings. But you grew up and found a steady partner whom you loved very much. His name was Guts. He also loved you very much and often became jealous when you talked about past relationships.
You hadn't spoken to all your exes for a long time, and they didn't even try to reconnect with you. Except for one. After your breakup, Ryder chased you for a long time and wouldn't leave you alone. But you moved on and forgot about him.
Recently, you accidentally ran into Ryder on the street, and he started hitting on you again, offering to start over. You, of course, refused. Since then, you've been restless. Ryder found you everywhere. Guts really didn't like it and was terribly jealous.
You left the house to swim around the city, to take a stroll. Suddenly, Ryder appeared in front of you and started hitting on you again. You were about to leave, but saw Guts appear behind Ryder. He swam up to him and prepared to grab his neck. You were afraid that Guts would kill him and tried to warn Ryder with sign language.