My sister accused me of upstaging her at her wedding after I turned up in an £2,500 Alexander McQueen gown – but do YOU think it’s too much?

A woman has sparked heated debate after showing up to her sister’s wedding in a £2,500 designer dress.

Earlier this week, the anonymous woman from the UK explained how she wore an Alexander McQueen dress to her sibling’s recent wedding.

The pink silk dress had an elegant sweetheart neckline and draping at the back that gave the illusion of a little train.

Post on Reddit’s ‘Am I The A*****’ forumthe 21-year-old said she misunderstood the invite and thought the dress code for the event was black tie optional.

As such, she paired her floor-length dress with some pearl earrings and a necklace bought by her fiancé – who was dressed in a black tuxedo.

But when the couple arrived at the event, the woman was horrified to discover that the wedding was “more semi-formal” and resembled a “cocktail party.”

She wrote, “My dress looked more flowy and classy than my sister’s, who wore a modern-looking dress that was nice and form-fitting, but not as formal. We were so ashamed.’

The woman went on to say that her dress upset her sister – who felt the spotlight was being taken away.

She continued, “My sister came up to me and asked what I was doing and told me it’s her wedding not mine and she hated that I ‘showed her up’.”

At that point, the woman’s fiancé stepped in and took “responsibility” for buying the formal dress.

In response, the bride reportedly called him a “disgusting snob” and said he “should have known better.”

The woman added: “We left just after that and now everyone is annoyed with us because we missed the wedding.”

In just four weeks, the couple are getting married and they’ve asked their guests to dress formally for the occasion – with the option of a black tie.

The floor-length designer dress featured a sweetheart neckline and back drapery that resembled a short train

Dozens of unimpressed Reddit users told the woman she should have shown her sister the dress prior to the wedding

However, the bride-to-be is concerned that her family is not dressing appropriately for her wedding and looking more casual than she would like – which she says would be “embarrassing.”

The dilemma sparked fierce debate among users – with many claiming the woman should have shown her sister the dress ahead of her special day.

One replied, ‘I don’t really think an expensive ‘floor-length’ designer dress is really appropriate for a wedding unless you’re the bride or a bridesmaid.

“It sounds like you didn’t bother checking with your sister to see if it was appropriate, so I’m more inclined to say [you’re the a******] even if the dress code sounds a bit vague, you have to be pretty ignorant to think it was okay.’

Another added, “Why did you play Disney Princess at someone else’s wedding?” How very novel of you.’

“Personally, I wouldn’t show up to a wedding in a $5,000 designer dress unless I was absolutely sure that was the vibe,” said a third.

However, others felt the bride was wrong for not being more specific about what guests could wear

Another critic objected to her partner’s behavior, saying, “I think your fiancée is the [a******]; I think he did this because he wanted to show off the things he bought you.

‘Formal doesn’t mean black tie; some uncertainty and he or you could have shown your sister pictures of your outfits beforehand.’

Others, however, argued that the bride was at fault as well, but wasn’t clearer about how she wanted guests to dress.

One user saw both sides and commented, “This could have been avoided with a little communication, but I think you’re both overthinking this. Just apologize for the honest miscommunication and move on.”

“That’s perfectly acceptable formal wear at a wedding,” said another. “It’s not white either.”