Breaking the ULTIMATE wedding taboo

You’ve made it through the ceremony without a hitch.

Your dress, which took you months to source, has been inundated with compliments and showered with admiration.

And every so often, you can’t help but glance with pride at your new husband.

In short, your Big Day is going swimmingly – you’re overjoyed.

Until, that is, one of your guests marches up towards the top table, gets down on one knee mere metres from where you and the groom are seated, and proposes to his already squealing girlfriend.

A few gathered invitees whip out their phones to capture the moment, and a few more break into awkward applause.

You’re simmering with fury, but all you can do is grin and bear; smiling through the intense anger.

This scenario may seem implausible – but for one seemingly unsuspecting bride and groom, this is an incident they were recently forced to endure on their own wedding day.

The moment has since been shared on Reddit, garnering some 3.7m viewers and more than 1,500 comments.

And understandably, the online reaction has largely sided with the newlyweds.

"This is up there with my uncle giving my cousins a puppy at my birthday party," remarked one user. "That's the saddest thing I've ever heard," another uttered sympathetically.

"That is the f***ing definition of 'stealing my thunder' right there," someone else stated. "Her smiles says 'congratulations', her eyes say 'that b***h'," one user wrote.

A minority, however, failed to see the issue: "Why is this a problem?" one asked. "It's supposed to be a happy night and this would make the bride happy if she was her sister etc."

It is believed that the event took place at a recent wedding in the US, though the bride and groom remain unidentified.

The newly-engaged couple have also yet to declare themselves publicly.