We're hosting my soon-to-be 6 year old's birthday party at our house this summer, and we invited his whole kindergarten class plus a few extra friends because he was so excited about it. I just sent out the evite yesterday, and I didn't specify whether or not siblings could come. It's just before a long holiday weekend, so I was thinking that some people wouldn't be able to come. Of course, so far almost everyone has said yes and several people have RSVP'd for more than one kid. I'm kind of freaked out that we're going to end up with like 70 people coming between parents and kids, way more than our house and yard can fit.
Since it's not a venue with a guest limit or paying per person, I feel more uncomfortable saying no to siblings/specifying that only the classmate can come. This is especially true for 2 reasons - 1. I didn't put it on the invite from the start. 2. Several kids in his class are twins (twin is in a different K class), and S knows the twin too. (Though this isn't the case for everyone who responded yes with more than 1 kid)
WWYD? I could add it in now, or wait until more people RSVP to see if it's really going to be a problem. Would you be offended/ think it's weird to have a no-siblings rule if it's a party at a house? I'm thinking the wording could be something like, "We're so happy that so many people are able to celebrate with S. However, due to space limitations, we aren't able to accommodate siblings."
ETA: I'm also ok with it possibly being too late to change the invite and having to suck it up and hope that some people who haven't responded yet can't come.