Thought I'd share this with you ladies, I still can't wrap my head around the fact that this actually happened to us...
I got a FB message from FSIL (FI's brother's wife) the other day, wanting to know when we were sending out the invitations, I let her know around the 2-3 month mark. She replied saying, and this is verbatim "Well I just wanted to give you a heads up that we will be RSVP'ing for 6 of us, so you can add that to your count ahead of time." I'm thinking 6? You have 2 kids... who are invited as their son will be our RB. So I message her back "6? Who else are you RSVP'ing for?" She tells me the extra 2 are her mother and father... who I have never met... and I've only met her once (they live in Ontario). Honestly I thought she was joking at first. I called FI over and he was speechless.
After getting over the initial shock, I messaged her back saying "I'm sorry, but unfortunately we are at our limit for guests and won't be able to accomodate your mother and father." She replied back saying that it was custom in her family for the entire family, including the mother in father to be invited to weddings... Yeah that's great but I DON'T KNOW YOUR FAMILY! I am not required to invite them, they're strangers to me! (I didn't say this to her). I apologized to her again and told her I hoped they could still make it. No reply thus far. If this isn't a WTF moment, I don't know what is.