So our wedding is in about 5 weeks, we mailed the invitations a few weeks ago. A friend of FI's (whom I've met a few times but haven't see in years) RSVPed Yes, and this is when FI decides to tell me that this friend has had a girlfriend for 6 months that neither of us have ever met. Since I had no idea, he was not invited with a guest on the invitation.
So is it more rude to invite this girl now (and take the chance she thinks she was B-listed) or just not invite her? I'm considering fibbing a little bit and saying the "and guest" was just accidentally left off the inner envelope or something.
Thoughts?