02:50 PM EDT 03/19/2015
Originally posted 01/12/2010 08:30AM
It's been more than two decades since Brittny Gastineau's father Mark, the legendary New York Jets player, left Brittny's mom Lisa for actress Brigitte Nielsen. But it wasn't until last week that Brittny met the fruit of that union: her half-brother Killian Marcus Gastineau, who's now 20.
Brittny had never before seen or spoken to Killian, who lives in Italy and works at a wine and champagne company. "I've always known I have a half-brother, I was told as a kid, but he was totally off the radar. It was like he didn't exist," Brittny tells PEOPLE.
But Brittny's mom bumped into Nielsen at Ivana Trump's wedding last year, and they exchanged phone numbers – and, surprisingly, pleasantries. Then, last week, Nielsen "texted my mom and said Marcus is in town and he'd love to meet me," says Brittny.
Top 5 Most Voted Stories
The Untold Story of JFK's Sister, Rosemary Kennedy, and the Disastrous Lobotomy Ordered by Her Father
Students Walk out of School After Transgender Classmate Is Allowed to Use Girls' Locker Room: 'I Am a Girl. I Am Not Going to Be Pushed Away to Another Bathroom'
'What Have We Done to You, Rosie?' Distraught Rose Kennedy on the Lobotomized Daughter She Didn't See for 20 Years
Jessa (Duggar) Seewald Publicly Turns Her Back on Brother Josh – Is a Family Feud Brewing?
Avril Lavigne and Chad Kroeger Are Separating: 'We Are Still, and Forever Will Be, the Best of Friends'
Top 10 News Categories
The most buzzed about stars this minute!
Treat Yourself! 4 Preview Issues
More On PEOPLE.com
Got a News Tip?
Send it to our People.com editors!