A friend of a friend was getting married around the same time I was. She told me that she was thinking about inviting two of her cousins but not the other one, because she wasn’t as close to him.
I mentioned that etiquette says that, as a general rule, you should be consistent with whom you invite. You can invite all your cousins, or none of them, and either way no individual can get offended.
She replied, “I don’t really care what etiquette says.”