1. Asking to bring a date who wasn't explicitly invited
McNeeley said this happened to her — twice! — while she was planning her own wedding. And she's seen it happen multiple times to her clients.
Sometimes, an invitee will ask one of the hosts if they can bring their kids or a date. Other times, they'll be so bold as to write in someone else's name, along with theirs, on the RSVP card.
"This is a big faux pas, and really bad manners," McNeeley said.
It's not just that your hosts didn't budget for an additional guest, McNeeley added — they may also want a more intimate wedding.
Putting your hosts in that awkward position, she said, "puts a weird damper on it."
2. Deciding at the last minute that you want a different meal
If you indicate on your RSVP card that you'd like the fish, it's really rude to request the filet mignon right as the waiters are passing out dinner.
"It puts a backlog on the food service," McNeeley said, which affects all the other guests, too.
Obviously, if you have a food allergy or another dietary restriction, you'll want to let the hosts know beforehand — and most people do, McNeeley said. But it's not okay to simply decide that one dish looks more appealing.
"If you're a guest and someone is serving something, graciously accept that."
3. Getting ridiculously drunk
McNeeley has seen this happen — and it can be at least "a little troublesome," she said.
4. Giving a long-winded toast
When it comes to speeches, McNeeley said, keep it to two minutes or less.
It's okay if you go a little bit over, she added. But "it is a faux pas when you completely hold the whole room hostage and speak for 15 minutes and nobody's interested," she added, especially because it stops the wine and food service.
Similarly, McNeeley recommends that you avoid giving impromptu toasts. "It just becomes awkward and embarrassing," she said, and much of the time, the person giving the toast is drunk.
In that situation, McNeeley said, "You think it's so great, but it's not as great as you think it is."