What was supposed to be a joyous day for Britney Spears ended in police handcuffing an uninvited wedding guest on the pavement outside the pop star's home.

On Thursday, the "Toxic" singer's first husband Jason Alexander, whom she divorced 55 days after their spontaneous Las Vegas wedding in January 2004, showed up at her home in California, where he broke in and claimed he had been invited.

Alexander livestreamed the attempted wedding crash on Instagram.

Footage shared on social media shows him approaching security guards outside the pop star's home, seemingly during preparations for the nuptials. He tells the guards that Spears personally invited him and that she was his "first and only wife" before his phone stream appears to freeze.

In other footage, Alexander is seen being asked by a guard to leave as he warns them not to touch him. He eventually makes his way into the house where he searches for Spears, before introducing himself to guests outside.

At one point can be seen wandering around the ceremony location, complete with pink and white roses.

After a few moments, a man on a cellphone approaches him and asks why he's there.

According to TMZ, the Ventura County Sheriff's Department responded to a trespassing call and arrived on the scene, where Alexander was restrained and arrested.

Speaking to TMZ, Spears' attorney Mathew Rosengart shared he was "absolutely livid" about the incident. He also confirmed the singer's safety and shared he is "personally working with the sheriff's department to ensure Mr. Alexander is aggressively prosecuted to the fullest extent of the law."

Later, Spears' assistant Vicky T shared her thanks to fans via Instagram for alerting her to Alexander's livestream.

"I've done everything I can while being out of the country to keep everyone safe," she wrote in an Instagram Story. "Thank you to all of the absolutely amazing and incredible fans for alerting me of so much. You are blessings, thank you. Everyone is safe."

"Truly, y'all are heroes for commenting/tagging and making a fuss about this. That could've really gone much worse and you played a part in keeping her safe," she added.

Alexander famously showed support for his ex-wife during the #FreeBritney movement outside the courthouse in August 2020 when her conservatorship was terminated.

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