Olivia Wilde poked fun at herself for wearing a white wedding dress to 'Bachelor' alum Colton Underwood's nuptials

• Olivia Wilde attended Colton Underwood and Jordan C. Brown's wedding on Saturday.
• Wilde wore a white slip dress to the nuptials that looked like a wedding dress.

Olivia Wilde embraced a fashion faux pas at a wedding over the weekend.

On Saturday, former "Bachelor" star Colton Underwood, 21, married political strategist Jordan C. Brown, 38, at a resort in Napa Valley, People reported.

Wilde was one of the 200 guests who attended the wedding. According to Just Jared, the "Don't Worry Darling" director has been friends with Brown "for years," and she has been featured on his Instagram page multiple times.

Brown even referred to her as one of his "dearest friends" in a 2019 post, so it's no surprise Wilde gave a speech at his wedding, as she shared on her Instagram story.

Wilde posted a photo of herself from the wedding ceremony, holding a parasol and wearing a white dress from Nili Lotan. The white dress dipped into a low V in the back, and it had a subtle mermaid skirt.

It looked like a casual bridal dress, which Wilde poked fun at in her post.

"Wore a wedding dress to a wedding just so I could make a joke about it in my toast," she captioned the photo.

It's typically considered a faux pas for guests to wear anything that may take the spotlight away from the couple getting married, which could include white outfits, bold colors, or daring looks.

But Wilde is no stranger to taking fashion risks, as she often appears on red carpets in daring ensembles. The actor made clear, however, that the newlyweds didn't mind her choice of outfit for their wedding, following up her photo of the dress with another of her hugging Underwood as Brown looks on.

"The grooms approved," she captioned the shot.

Underwood started dating Brown in the summer of 2021 after coming out as gay the same year.

At the time, he also issued an apology to his ex Cassie Randolph, who won his season of "The Bachelor," which aired in 2019.

"I would like to say sorry for how things ended," Underwood told Robin Roberts of what he wishes he could tell Randolph on "Good Morning America" in April 2021. "I messed up, I made a lot of bad choices."

Ahead of his wedding, the former NFL player told People he had "never been more sure about something" than he was about marrying Brown.

"He has the biggest heart and he's such a good friend to all of the people in his life," he told the outlet. "He goes out of his way to take care of his friends and his family. That speaks volumes. It was one of the first things that I noticed about him."