To be annoyed with future MIL

[LuLuBeth]

DP and I have had to bring our wedding forward in order to be certain we can marry this year for fear of a second lockdown happening in the winter. We have arranged a very small intimate wedding with family only, we were allocated 30 guests (we've got 34 but the vicar said he can make it work). We have only got 2 people on the guest list, DP's best man and his wife, who aren't family.

DP's siblings have all got partners but none of them are married, his sister (lets call her L) has been having issues with her boyfriend (let's call him K) and we weren't sure if we should invite him or not but after a discussion with his other sister we decided to invite him.

We popped over to DP's mum yesterday for a social distance cuppa in the garden and whilst we were chatting she mentioned how L was coming but K wasn't and since K wasn't coming she decided that L would bring DP's step sister (who isn't actually his step sister as his mum isn't actually married to her partner), DP hardly knows her and I have met her once and she didn't even speak to me. DP's mum justified this by saying how DP's sisters are close to her etc.

If we were having a normal wedding I wouldn't be so annoyed, but it's the fact that I haven't even invited my best friends or other blood family members and DP hasn't invited his friends because it's such limited numbers. DP and I had spoken previously about what we'd do if people couldn't make it and we decided that we would not invite anyone else as we'd already gone over the allocated number.

DP gets why I'm upset but doesn't see it as a massive issue as it's not like it's an extra person or it's a space we could give to someone else because we'd said we weren't replacing people with others and he does have a point. But I think what's annoyed me is the fact that they never asked and we COULD have had someone else we wanted to invite.....

Well tell her not to come then?

I would have told his mother this isn't happening. That slot can go to someone actually close to you. Set boundaries, op. She can't just arbitrarily invite someone to your wedding.

Even if you were not so limited on numbers it is not up to her to decide your guest list. Tell her no, step sister isn't invited and there will be no more invited unless 5 or more people can't attend.

I would tell them you actually could use that space for Uncle John (or whoever). It's your wedding. I do think it's off to invite someone to someone else's wedding. But, tbf, she may just have thought "cripes, LuLu and Stb Mr LuLu wont want the space to go to waste, so we'd better fill it". She may have been trying to save the space and your money from going to waste.

I'd just tell your partner to tell his sister that the stepsister cant come due to numbers. Everyone knows covid has affected numbers to weddings. Dont go through the mil, go to the source. I've had experience of mil telling me things that turned out to be not true. For all you know, the mil has told her daughter you were fine with it

"Even if you were not so limited on numbers it is not up to her to decide your guest list."
This

It is a big deal if you could have someone you actually cherish there on the day instead of a distantly related place filler.

Tell your DH it upsets you, and it won't be missed in such a small wedding, and to tell his DM to uninvite her.