Boy troubles

There's this guy that has been getting on my nerves I really don't like him. And he's on a fetish website. And he's basically threatening me by saying that if I don't continue to talk to him, that he'll leak my number to ther people and they'll talk to me, I don't want that to happen but I don't want to be in contact with him. He made me believe I could trust him and now I regret it. What should I do?