Todd Williamson/Getty; Chris Farina/Corbis/Getty Britney Speras and Jason Alexander
Britney Spears is safe after her ex attempted to foil her big day.
The Ventura Sheriff's Department arrested Spears' ex-husband Jason Alexander on an outstanding warrant Thursday as he trespassed at the Grammy Award winner's private wedding venue hours before her planned nuptials to fiancé Sam Asghari, PEOPLE can confirm.
"She's freaking out over this," a source close to Spears, 40, tells PEOPLE.
Alexander, 40, Livestreamed himself on Instagram as he roamed around the property, revealing their wedding decorations, which were still being arranged by party planners. He could be heard yelling her name and claiming to security that he was invited to the wedding.
"So, here's the inside scoop, guys, of the bull— wedding. Jason Alexander, what's up," he said, greeting the workers and even shaking one's hand.
"My name's Jason Alexander. Britney invited me here," Alexander claimed. "Britney Spears invited me here. She's my first wife, my only wife. I'm her first husband. I'm here to crash the wedding."
Spears' assistant Vicky T, who was alerted to the trespassing by fans on Instagram, has since provided an update, assuring that the bride-to-be was unharmed.
"I've done everything I can while being out of the country to keep everyone safe," Vicky wrote on her Instagram Story. "Thank you to all the absolutely amazing and incredible fans for alerting me of so much. You are blessings. Thank you. Everyone is safe."
The Glory artist was married to Alexander, a childhood friend, for 55 hours in Jan. 2004, after the pair eloped at the Little White Wedding Chapel in Las Vegas.
Alexander previously pleaded guilty in January to violating an order of protection and aggravated stalking against an unidentified woman, TMZ reported at the time. He was given 11 months and 29 days of probation.
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"Britney started planning and dreaming about her wedding shortly after she got engaged in November," a source told PEOPLE. "She has enjoyed the planning, but also felt stressed about it."
"It's a huge deal to her that she is finally able to get married. She wants it to be perfect. She is so excited that she feels overwhelmed. She is very emotional," the insider added.
Spears began dating Asghari in 2016 after he appeared in her "Slumber Party" music video.