Dwyane Wade Says Telling Gabrielle Union He Had a Child with Another Woman Was the 'Hardest Thing'

Dwyane Wade has had a lot of ups and downs in his life, but the “hardest thing” he’s ever had to do was tell Gabrielle Union that he had a child with another woman, according to his new ESPN documentary.

In his upcoming D. Wade: Life Unexpected, the former Miami Heat superstar, 38, opens up about his personal life and his brief split with Union, 47. Recalling their reconciliation, Wade says it “wasn’t easy” to let the actress know about the son he fathered during their time apart.

At the time, Wade was already dad to Zaire, 18, and Zaya, 12, and nephew Dahveon, 18. He welcomed Xavier, 6, with Basketball Wives star, Aja Metoyerin, in 2013 shortly before proposing to Union.

“I had a child with someone else and I had to tell her. Hardest thing I’ve ever had to do is man up and tell Gabrielle Union that I’ve had a child with somebody else,” he says in the upcoming sports special, according to Entertainment Tonight. “I couldn’t sleep. I wasn’t eating.”

RELATED: 21 Sweet Photos of Gabrielle Union & Dwyane Wade’s Family That Prove They’re #FamilyGoals

He continues, “When you hold something in that you know is going to come out and you have this information and you know it’s gonna f— somebody’s life up, that you care about, that you love, if it don’t hurt you, then you’re not human.”

The NBA star adds in the documentary that he and Union “went through something that you never want to go through and we still came out of it,” according to ET.

Wade married Union in August 2014. The couple welcomed daughter Kaavia, 1, via surrogate in 2018.

In her 2017 book We’re Going to Need More Wine, Union shared that she struggled with infertility and failed IVF treatments when she was trying to expand her family with Wade.

“I have had eight or nine miscarriages,” she shared in the collection of personal essays. “For three years, my body has been a prisoner of trying to get pregnant — I’ve either been about to go into an IVF cycle, in the middle of an IVF cycle, or coming out of an IVF cycle.”

But even after enduring three years of failed IVF cycles and being constantly bloated from the hormones, Union wrote that she and Wade “remain bursting with love and ready to do anything to meet the child we’ve both dreamed of.”

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

Earlier this month, Wade announced another big change in their family when he sat down with Ellen DeGeneres on her talk show and opened up about the moment Zaya came out to him and Union.

“Me and my wife Gabrielle Union are proud parents of a child in the LGBTQ+ community,” he said. “And we are proud allies as well. We take our roles and our responsibility as parents very seriously. So when our child comes home with a question, when a child comes home with an issue, when a child comes home with anything, it’s our job as parents to listen to that, to give them the best information that we can, to give them the best feedback that we can — and that doesn’t change because sexuality is now involved in it.”

RELATED: Dwyane Wade Proudly Opens Up About Watching His ‘Son Become Into Who She Now’ Is

The retired basketball player continued, revealing that his child had decided to go by the new name of Zaya, and be referred to by she/her pronouns.

“So once Zaya, our 12-year-old, came home — first Zion, I don’t know if everyone knows, originally named Zion, born as a boy — came home and said, ‘Hey, I want to talk to you guys. I think going forward I’m ready to live my truth. I want to be referenced as she and her, I would love for you guys to call me Zaya,’” Wade shared.

“Once Zaya came home and said, ‘I want you to call me Zaya and I’m ready to take on this,’ I looked at her and said, ‘You are a leader. And this is our opportunity to allow you to be a voice,’” he added. “Right now it’s through us, because she’s 12 years old, but eventually it will be through her.”