Weddings are supposed to be fun — guests enjoy the free booze, hit the dancefloor, and laugh at the speeches.
But it's a whole different kettle of fish for those lucky enough to score an invite to Prince Harry and Meghan's wedding at St George's Chapel in Windsor next weekend.
There'll be more royals than you can swing a tiara at — and with royals, come rules. Lots of rules, reports news.com.au.
Here are some of the major rules guests will need to abide by:
The sad truth for those of us watching from home is that we're unlikely to see anything at all once the wedding party and attendees have entered the church.
As former royal editor Duncan Larcome told Cosmopolitan UK, phones will need to be put away as soon as the Queen enters the room — which, of course, will be before the bride.
"A royal wedding is the only time that the Queen isn't the last person to walk into a room — she has to wait for a bride. Once the Queen is there, guests will be on their best behaviour. Things like tweeting will be an absolute no-no."
And forget about catching a snippet of Harry's speech at the afterparty.
"Guests will be told not to take pictures at any part of the day, particularly during the evening reception at Frogmore House," Larcome said. "No pictures ever emerged from William and Kate's party — anyone who broke this rule would certainly end up in hot water with the happy couple."
All 800 of the guests inside the chapel will have assigned seating. The allocations will follow tradition — the bride's family on the left and the groom's on the right.
"Meghan's parents, co-stars and friends will be given priority seating on the left," Larcome told Cosmopolitan.
"In a way, they will be trying to make it as normal a wedding as possible. So, when they look around they will both see their families."
This is standard for anyone who encounters Queen Elizabeth II, but many guests at the wedding will be new to the world of British royal etiquette.
All of those in attendance will be expected to bow or curtsy to the reigning monarch, and will also be required to call her "Your Majesty" upon first introduction. After that, they can chill out a bit and call her "Ma'am."
It's surely pretty exciting to spot the Queen, but forget about approaching her.
"Normal protocol suggests you shouldn't approach the Queen or ask her any questions," said Larcome.
Instead, guests are expected to wait for her to address them directly.
Unlike Prince William and Kate Middleton's wedding in 2011 — which required some guests to arrive two hours early — Harry and Meghan's nuptials will be a little more relaxed.
However, guests will likely need to arrive an hour beforehand, giving plenty of time for everyone to settle in before the Queen arrives, just minutes before the bride.
Prince Andrew has been asked not to attend the royal family Christmas lunch this year.