I'm going to be standoffish with my younger cousin
Why do you want to act like that?
He's totally annoying and he's totally annoying and always wants to play with me.
They just want attention and to have fun. It'd be rude to act that way towards him.
I don't care. He's an annoying kid and I need some time alone anyway.
It's easy to see why he could get on your nerves. But he is a kid and just wants to spend time with you. Thinking of it as him liking you and wanting to spend time with you because your good person would probably change your mind on the situation.