Most 'rules' for what you can and can't wear to weddings these days are supremely outdated: no white dresses, no black dresses, a tie always required, etc.
But even with more relaxed guidelines, one woman's outfit has raised eyebrows online, with commenters questioning if she was "stealing attention from the bride".
A photo of the anonymous woman and her partner was posted into the subreddit 'Wedding Shaming'.
"Hot wedding guests, but talk about stealing attention from the bride with that sheer dress!" wrote the Redditor who posted the image.
The post doesn't reveal how the bride reacted to the bright red number, but commenters agreed the dress was an inappropriate choice, especially for a day wedding.
"I feel like she's gotta have some beef with the bride, that dress way too hot for a wedding lol," wrote one person.
"It looks like literal lingerie," wrote another.
"Maybe her ex is a groomsman," joked another.
But others pointed out it might fit with the aesthetic of the wedding, especially given modern trends.
"I'd be interested to know what the bride, bridal party, and other guests are wearing. While this is much too risqué of a dress for me and my circle, I can see it being the norm for some circles, especially the flashy lifestyle influencer ones," one person pointed out.
"If I had a body like that I'd dress like that every damn day," wrote another.