So I am in a group chat with my family. We’ve had this groupchat established for a long time, and none of us have ever added anyone else to it. Somehow last night, a different family member joined our group chat and started texting us, but none of the original chat members added her, not even accidentally. This is the second time this has happened, and we have no idea how they are inserting themselves into our group chat. We are all iphone users, including the person that is somehow adding themselves to our group chat. All of us use different Apple ID accounts as well as different phone numbers, and that’s the same for the person adding themselves, so I’m truly at a loss for how this is happening.