In all my years, I've never heard of such wheeling and dealing behind the bride's back. I'm simultaneously appalled and amazed at this...
I actually have to go make some tea right now to calm down on your behalf...back in a sec...
Okay, I'm back. Your MiL is very clearly in the wrong here to overstep your wishes, break most of the etiquette rules ever invented, manipulate your groom (who I'm sure doesn't want to be the Middleman), and put HER guest wishes over yours. You have every right to be upset, and I'm ready to come out there and put the woman in her place.
It's very upsetting when someone you thought you had a great relationship with does something so insidious in an effort to 'beat your system.' I'm trying to give her the benefit of the doubt, but it's quite difficult to do so. She has agreed to stop her bad habit, and has continued to do so, feeling like she has the right to insert her guests where yours should be.
She has become a Steamroller Mom. Perhaps somewhere in there, she feels she has good intentions, that she's not doing something too awful, but she really is. I've heard everything, and this is one of the saddest practices I've ever heard of. Is it her personality to be the I'll Do It person, someone who always has to get her way? We all know plenty of people like that and it's a personality quirk that can be maddening. But it seems to be part of her hard-wired personality. Unless I'm totally wrong -- and please correct me if this seems way outside her usual bounds of behavior. She may have just gotten caught up in the excitement of the wedding and lost her mind a little bit -- which happens even to the most mild-mannered, considerate and loving mothers out there. I could tell you some stories...where bounds were crossed and the mothers woke up the day after the wedding with a 'what did I do' and piles of regrets.
That said, we know you want to have a great relationship with your MiL and are justifiably upset about the problems and extra work she has caused. You've been hurt, and the next smart step is to find a solution.
I advise you to meet with her in person, so that she can SEE how hurt you are. This doesn't mean you should cry and look depressed, but just let her see that you are on to her actions and they've affected you deeply. Sometimes people take pride in their ability to 'make things happen' for themselves and they count on the other person -- with their good nature and kindness -- to just let it go. Sounds to me like your MiL counted on that.
She's made something of a mess, but luckily the numbers of extra guests she added are pretty low. It's the principle, I'm sure, that in the beginning of your relationship, she's showing you no respect. And anyone would be nervous about seeing the groom unable to stand up to his mother.
I have some steps for you:
1. Set up a meeting with her, just the two of you. The groom is clearly indoctrinated by her ways, and he rightfully feels uncomfortable with feeling pushed into changing the dimensions of his relationship with his mother after so many years of acceptance and perhaps not being confrontational (Reality check: is this something you love about him? That he goes with the flow? Often our guy's best quality has a flip side.)
2. Explain to her that while you understand her intentions are good, and that she just wants to share the day with people who are important to the family (you're taking the High Road and giving her way too much credit than she deserves right now), you absolutely must insist that she stop calling your guests and taking their guest spots. (You're calling her on her actions and in stating your interpretation, which you can back up by saying that some guests have expressed a displeasure with feeling pressured about handing over their And Guests). It will register with her that others aren't pleased. Moms with a well-greased manipulation factor often use it on people they think they can 'work.' It often scares them when others may be able to see right through them.
3. Stay calm. Don't put her on the defensive. That's the worst way to come to a resolution.
4. Tell her how it's going to be, that any open spaces in the guest list have already been reserved for your additional friends and colleagues, and how much it means to you and your groom to have your people there.
5. Tell her you have the master guest list, and any more surprises will be met by your directly calling the guests in question to change the And Guest status. you don't look forward to it, because it's an awkward situation, but you feel strongly about having your wedding surrounded by your family and friends. You hope it won't come to that.
6. Avoid telling her about the extra work she's caused in printing out the extra stuff. I hate to say this, but I don't think that will spark an empathy response. So avoid anything that tries to pull at her heartstrings.
7. Suggest that she and her husband plan a wedding vow renewal celebration of their own! Smile and be excited for her, saying "I can see how excited you are about this wedding and how much you want to celebrate with your friends. So why don't you do as SO many parents of the bride and groom are doing, and plan your own separate celebration for another time?!" Tell her I'd love to talk with her and can help her plan her event with advice from my new Vow Renewals book coming out in December (which was inspired by exactly these kinds of situations...parents running amok with the wedding plans). I think she might love the idea and it will switch her focus to her own celebration, even a small informal one where she gets to be the center of attention. Plus, all the guests will be hers to plan. I find that parents who get impulses to steamroll a wedding really have a deep desire to have their own celebration for themselves. This could be a great option here.
8. Express your wish to have a close, loving relationship with her. Tell her how much you've enjoyed being welcomed into their family, mention specifics like the time she showed you the family albums, and express a desire to plan some outings with her where you can BOTH get a break from the wedding plans (even if it's just going out for coffee). You love your groom, and you love his family, and it's a proven fact that a close relationship with the in-laws helps make a marriage better. This way, in dealing with her outside of a situation that clearly brings out a shadow part of her personality, you can establish more common ground on better things. Your groom will be pleased that you are so gracious, mature and forward-thinking, and that you want to bond with his mom.
A note about the groom, please don't worry about your relationship with him or the fact that his mom has a pull on him. That happens so often. Rather than try to change their relationship -- which, I know, you didn't say you want to do; I just thought I'd bring it up for others who are reading this -- accept that even a great relationship has some bumps. You can't change the hold she has on him now -- a grip that naturally tighens before a wedding due to fear of loss and change -- but you can add on pleasant experiences and memories that build a future for you all.
Again, this is pretty crappy of her to do, but it presents an opportunity for you to nicely and respectfully approach her with some groundrules that are SO going to pay off in the future. It's going to take time for her to learn how you work. And it's going to take time for you to accept this bossy side of her and love her anyway. But I really do think that a direct conversation that's GOAL-ORIENTED, as opposed to calling her out, is the best way to go.
I don't know the details of your background, so please forgive me if I'm off base anywhere here. Write me back with more details if you wish -- I have a thick skin and don't mind hearing if I've misinterpreted something here -- and we'll talk further about this very important conversation.
I'm sorry this happened to you, but I really do think you can swing it to your advantage and set up a foundation of respect for your future relationship.
All the best,
Sharon