I'm posting this to try to help other brides who are trying to find a way to avoid those plus ones without calling 50% of the guests and saying no. This way, you will avoid almost all of those!
I've been researching how to avoid unwanted plus-ones. This is not a debate on who should be allowed to bring a plus one. All of the advice in various locations said to put "and guest" on the inner envelope. Great! Who the heck uses inner envelopes anymore? I have never seen one. I've also seen people say that without an inner envelope, they just put it on the outer. They say that if "and guest" isn't there, the invitee will catch on. Well, after snooping around on various boards, it was clear that invitees do NOT catch on. So I started looking for another solution. And this may be a breach of Miss Manners' version of etiquette, but I'm pleased with it.
The RSVP cards are worded like this:
The favor of your reply is requested by [date].
We have reserved _2_ seats in your honor.
___ people will be attending.
Mr. and Mrs. John Smith
___ Accepts with pleasure
___ Declines with regret
We will fill in the name and the seats reserved. The people attending one is left blank, for them to put a number and the lines by accepts or declines are left blank for them to check. Would Miss Manners disapprove? Oh yeah. Will most of you Knotties? Probably. Will it get my point across? Yep.
Now, it is worth noting that other brides who have done this have had those few people who will actually cross out the number and write in a new one. If I get any RSVPs like that, I will have no issues calling and saying no.