I'm going to avoid calls from my little cousin who is quite attached to me
Why are you going to ignore your cousin's calls?
Because he wants to talk to me too often. I hate the kid.
You shouldn't ignore your cousin's calls. They look up to you and before you know it they will mature and move on.
He's just an annoying little fuck.
If he calls you too often, it's okay to tell him you're busy sometimes. But you should try talk to him frequently. It's good for kids to have role models and it's important to be kind to younger relatives.