Thomas was supposed to walk Meghan down the aisle, but on Monday, the retired television lighting director pulled out of the ceremony after he was pictured allegedly staging paparazzi photos.
Thomas (73) is reported to be "deeply embarrassed" by the stunt while Meghan is said to be in the midst of a "deeply personal moment". To make matters worse, last night TMZ reported Thomas had changed his mind yet again, telling the site: "I hate the idea of missing one of the greatest moments in history and walking my daughter down the aisle."
We may not be able to grasp the complexities of Meghan's relationship with her father, but we can all, in our own way, understand the emotional entanglements that go hand in hand with weddings.
Yes, weddings bring people together, as small-talking guests are wont to say after a few celebratory glasses of Prosecco. Add money, social hierarchy and a misplaced sense of propriety to the mix, however, and they can tear people apart too.
A wedding is billed as a celebration of a couple's nearest and dearest, but the couple's farthest and flakiest have to be identified first. For better or worse, nuptials are designed to separate a soon-to-wed's inner circle from their outer ones - and the process is far from seamless.
The schisms appear shortly after an engagement is announced. You may have read that schools in the UK have started to ban the term 'best friend' to stop children feeling left out. Brides and grooms are older and wiser but still they partake in the schoolboy silliness of choosing a maid of honour and best man - even if it means snubbing some of their closest pals.
Hen and stag parties are another exercise in social exclusion. The sister of the groom, or the brother of the bride, might be glad they've been left off the invite list. However, their omission can set a cold-shouldered precedent too.
Family roles come next. This part is easy to orchestrate when the parents of the bride and groom are still together. It can be a minefield when they are not.
Meghan's family drama has become headline news in recent days, but separated families are an unfortunate fact of life for many brides and grooms and tradition only adds to their troubles.
What happens when the mother and father of the groom haven't talked in 20 years? Should an estranged father or stepfather walk a bride down the aisle? Are second husbands and wives accommodated at the top table?
It gets even more complicated when there is money involved. A couple may have finally conquered the chess game that is a seating arrangement only to be told that one of their parents has invited half the golf club. They're "paying for the bloody thing, after all"...
People think it's the little touches - the sugared almonds, fresh-cut peonies and miniature chalk boards - that send couples over the edge. Actually, the real flashpoint is the social dynamics and the motley crew of characters a couple has to contend with.
A wedding involves bringing two never-the-twain-shall-meet groups of people together before throwing in a few notoriously tricky customers for good luck.
Can you put the colleague with the drinking problem and the cousin with the social anxiety disorder on the same table? What about the aunt who is deaf in one ear and the maudlin uncle who recites Bean Sléibhe Ag Caoineadh A Mhac after drinking too much whiskey?
Then there are the Fergies. The Duchess of York fell out of favour with the Royal Family after having her toes sucked by a Texan, writing a tell-all autobiography and getting caught up in a 'cash-to-access' scandal.
Like every other bride and groom, Meghan and Harry will have to negotiate this particular family feud and decide whether they want to bury the hatchet or twist the knife further.
When you consider the Gordian social dynamics of a modern wedding, it's little wonder couples spend the better part of the day having every possible permutation of their family tree photographed. Bride and groom with bride's family! Bride and groom with groom's family! After a painstaking guest list edit, they realise it's best not to leave these things to chance...
Later on, someone might make a speech about marriage bringing two families together, and someone else might read out a quote about what weddings really mean.
The couple will smile and squeeze their hands together a little tighter. Really, though, they'll just be glad they survived their baptism of fire.
Weddings are fraught with family drama and friendship politics. Meghan and Harry, like every other couple before them, will have to overcome the dysfunction and chaos together.
It's messy and it's sticky and it's complicated, but it's also what makes weddings truly romantic.