If your cousin notices how you took up their hobby and they say, “You’re a copycat! I can do it better!” or something of the sort, do not react. Just say, “Well, you’ve been doing it for years and I just started. " Then go and do something of that hobby and say, “Wow. I actually think this is a great project I did. " Pretend to say this to yourself when you’re around them. Then casually look up and smile, saying, “Have you completed a painting / project, etc. like this yet?”.