Leech
What is the definition of a leech? A family member? Someone who claims kinship only when there is a direct, distinct benefit to themself? Yes. I would definitely call that a leech.
So seriously don’t like people who belittle others happy moments - no matter how trivial.
I don’t like hypocrites. Things good to your face but seriously off away from you. Not surprised so many of them need some substances to ‘keep balanced’