if his parents were invited to the royal weddings there's a good chance they know the chattos! elijah is distantly related to the royals (the queen is his great aunt basically) and very keen to cause choas, maybe their families knew each other when they were kids? we could even do something fun and say that they used to loath each other when they were younger and constantly getting into scrapes with each other before they started to mellow out as teens and kind of bonded over the experience of fame?