The plus-one question is where things get thorny, mostly because it carries a financial burden. This isn’t a kitchen supper party where one extra body is no great shakes. It’s an occasion where cost-per-guest is around £300, according to current estimates. If you’re worried about who you’ll be sitting with, it’s okay to ask about seating arrangements. But it’s likely you’ll have a band of mates around you, or if not, remember that weddings are typically friendly functions.
Children, much like plus-ones, are only welcome if explicitly invited - although if you have a babe in arms, it’s probably okay to ask. Sure, costs are less of an issue - babies don’t tend to knock back booze and canapés - but kids change the vibe, and not always in a welcome way.
If these are the biggies, then there are the smaller dilemmas. Do you need to bring a gift, even if the whole weekend abroad has cost a fortune? Yes, that’s part of the deal. If the couple in question has said no gifts, respect that, but maybe consider a gift voucher for a fancy restaurant instead. And about moving the place card - technically, this is a no. Someone has likely spent hours mentally jiggling those around like a game of wedding Tetris. On the day, however, a subtle rearrangement at a lower tier table will probably go unnoticed.
What it all comes back to is something very simple: weddings are not about the guest. They’re a rare opportunity to celebrate love and joy. This mindset applies to the happy couple, too - the more you accept that a room full of people from different chapters of your life will inevitably have its quirks, the happier you’ll be.
Just like the couple who gracefully made me feel welcome at their entire wedding all those years ago.