First lady Melania Trump may have broken the oldest rule in the wedding guest rule book.
Melania was spotted wearing a pink dress at U.S. Treasury Secretary Steven Mnuchin and Scottish-born actress Louise Linton's wedding, Yahoo! Lifestyle reported.
Photos of President Donald Trump and his 47-year-old old Slovenian-born wife standing next to the newlyweds, along with Vice President Mike Pence and his wife, Karen, have surfaced online.
In the photos, the bride does not appear to be smiling quite as big as the other women. Some people speculate that it may be because Melania stole the show with her sleeveless J. Mendel gown.
The pink dress, which some have argued is dangerously close to off-white, featured a ruffled top and long, flowing skirt. While elegant, the dress may have broken the number one cardinal rule for weddings, which dictates that guests not wear white out of respect for the bride.
But the first lady did not appear to be too worried about this rule, donning a pair of nude Manolo Blahniks shoes to go with her light-colored dress.
The bride was seen in a custom-made gown by Toronto designer Ines Di Santo, and, like the first lady, she also wore Manolo Blahnik heels. While she didn't appear to smile in the photo, there are no confirmed reports that she was upset by Melania's choice of dress.
Melania shared the photo on her Instagram account. Several social media users commented on the picture, most in awe of the first lady's stunning looks.
"Beautiful bride. Handsome groom. First Lady Melania looks gorgeous along with Karen Pence who looks just as gorgeous," wrote one commenter. "President Trump and Vice President Pence look very handsome as well."
"Most Beautiful People Ever!" declared another commenter.
"Fantastic many blessed years together," wrote another.
Other commenters couldn't help but notice that the bride's expression.
"That bride isn't really smiling, what's with that?" asked one commenter. "The Trumps look great and everyone looks great but no smiling bride is unfortunate."
"Bride looks like she wants to run," quipped another user.
"Most unhappy bride ever seen," another commenter wrote.
Linton met Mnuchin at a wedding reception in Los Angeles in 2013. Mnuchin, who is reportedly worth $300 million, proposed to the Scottish actress two years later when she stopped to admire the shape of an oval diamond in the window of a jewelry store, Express reported.
"We enjoy the museums and architecture," Linton said about their relationship.