A source exclusively confirms to PEOPLE that Long, 51, and Udoka, 45, have ended their 13-year-relationship after the former Boston Celtics head coach allegedly had an affair with a female subordinate within the team's organization.
"The situation is unfortunate and painful, but Nia is focusing on her children and rebuilding her life," the source says.
A rep for Long also confirms the couple are "no longer together but remain fully committed to co-parenting their son [Kez]."
"I think the most heartbreaking thing about all of this was seeing my son's face when the Boston Celtics organization decided to make a very private situation public," Long told The Hollywood Reporter last week.
In September, just weeks before the start of the 2022-23 NBA season, the Boston Celtics issued a statement on Udoka's immediate suspension from the team. At the time, they said Udoka had violated "team policies," and noted his future with the team will be evaluated.
Shortly before the Celtics statement went live, ESPN reported that Udoka had a "role in an intimate relationship with a female member of the franchise's staff." PEOPLE later confirmed the allegations.
Udoka later gave a statement to ESPN's Malika Andrews on the alleged relationship. "I want to apologize to our players, fans, the entire Celtics organization, and my family for letting them down," he said. "I am sorry for putting the team in this difficult situation, and I accept the team's decision."
His message concluded, "Out of respect for everyone involved, I will have no further comment."
Randy Shropshire/WireImage Ime Udoka, Kez Udoka, Actress Nia Long and Massai Dorsey
Long issued her own statement exclusively to PEOPLE following the news.
"The outpouring of love and support from family, friends and the community during this difficult time means so much to me," Long said to PEOPLE. "I ask that my privacy be respected as I process the recent events. Above all, I am a mother and will continue to focus on my children."
Long and Udoka had been engaged since 2015 and share one child together, 11-year-old son Kez.
The actress and the former head coach first met in February 2010 when Udoka was a professional basketball player with the Sacramento Kings. Long was in Boston filming a pilot for NBC, Udoka was playing against the Boston Celtics and a mutual friend set them up, according to the Boston Globe.
In June 2011, Long and Udoka exclusively revealed to PEOPLE that they were expecting their first child together. Long was already mom to son Massai from a previous relationship, but the new addition was Udoka's first child. Their son Kez was later born on Nov. 7, 2011.
During their relationship, Long was adamant how "marriage is not a priority for me," telling Essence in their August 2012 issue she had "never seen a marriage work" and that marriage didn't define a successful relationship for her and Udoka.
"I don't feel less loved or less loving because I'm not married," she said at the time. "I worked hard to have the career I wanted, but I've also been deliberate about my personal life. None of this is a mistake."
RELATED VIDEO: Nia Long Slams Boston Celtics, Says 'No One' Has Called to 'See If I'm OK' After Ime Udoka Scandal
Despite that, Udoka and Long got engaged in May 2015. Still, the pair had no plans to rush down the aisle, with Long telling a TMZ Sports reporter the following June that they were "taking our time" with wedding planning.
She shared similar sentiments in December 2020 on Essence's Yes Girl podcast, revealing that they didn't need the labels of husband and wife to know that they're "in a partnership."
Long added, "Love is complicated … and then you start a marriage, which I've never been married. And there's a reason for that because I don't know that I need to say 'I do' to prove to you that I love you. But also, what does marriage really [mean] … that you own me now and I own you? I don't get that part."
Maddie Malhotra/Getty Ime Udoka
In June 2021, Udoka was named the head coach of the Boston Celtics after serving as an assistant coach for the San Antonio Spurs, Philadelphia 76ers and Brooklyn Nets.
Long had also been busy with her own career in Hollywood, which currently includes starring in Peacock's limited series The Best Man: The Final Chapters, and the films Searching with Storm Reid and You People with Eddie Murphy, Jonah Hill and Julia Louis-Dreyfus.
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
Because of their jobs, the pair lived in separate states for a while, with Long and her son in Los Angeles and Udoka in Boston. However, Nia had recently moved her family to Boston to be with Udoka. She has since moved back to LA with her son.