There aren't a lot of rules to follow at a wedding, except one: You can't outshine the bride.
This woman though appears to have missed the memo after she turned up to a friend's wedding wearing a figure-hugging silk, white gown.
The unsuspecting guest left a review of the dress on Shein, an online clothing store, sharing a photo of herself in the full-length dress posing beside an elaborate flower wall.
"Perfect size, I like it so much and I wore this to a wedding and everybody kept looking at me. So sexy and simple," she wrote.
But things took an unexpected turn when it was then posted on Reddit's Wedding Shaming thread where users slammed her outfit choice.
Horrified commenters were outraged by the ensemble, branding the dress "tacky".
"Of course they were looking at you love, you're literally wearing a wedding dress to someone's wedding!" one said.
"Oh my. That's tacky af," another user wrote.
"Of course people are staring. They don't know who TF you are!"
Others claimed it was a "a good way to p**s a few people off".
Some explained what they would do if it happened to them on their wedding day.
"If someone ever tries this at my wedding I would ask them to change and if they refuse then I'll have them removed from the venue," one woman said, adding "it's my day and their tackiness and disrespect makes them uninvited".
"If I see this in my upcoming wedding, someone better stop me when I start walking to that b**ch with a glass of red wine," another furious user wrote.
One person called it a "straight up wedding dress" explaining the "rule".
"While honestly some people don't know about the white rule (I didn't until I was well into my 20s) but everyone should know not to wear an actual wedding dress to someone else's wedding!"
Others took issue with the dress being so crinkly, with one simply adding: "They may have also been wondering why she didn't iron it."
It's not the first time a wedding guest has been shamed over their outfit.
Last month, a furious bride publicly shamed her own cousin after she wore a skin-tight bodycon dress to her wedding.
Taking to Facebook, the anonymous newlywed shared the photo and begged someone to edit the outfit to make it look "smoother" and "cover up her boobs".
The offending cousin, standing on the far left, is dressed in a skin-tight olive green tank dress with a scoop neckline and a mini skirt hemline.
Captioning the photo, the bride wrote: "Can anyone edit my cousin's dress on the left to cover up her boobs, make her dress longer and her stomach smoother.
"I will donate $3 to my favourite edit. I have permission to edit. Thanks."