The actress, 41, was aware of the child before she accepted the Miami Heat guard's proposal on Dec. 21, a source tells the show, and the pair have worked through the issue privately. Wade, 31, has known the baby's mother for years and recently visited with his new son.
Wade spoke to Jay Leno on The Tonight Show in September about the break from Union, whom he had dated since 2009. The separation was largely due to the demands of their work lives, he explained.
"Celebrity relationships [are] very hard," he says. "This was a big year for us and our relationship from the standpoint of she was shooting her show Being Mary Jane, going most of the year. I was dealing with my injuries, trying to win a championship, so we kinda took a step back."
"We supported each other ... but at the end of the day we came back together and [said], 'Listen, we want to continue this, we want to continue to try to get better each day,' and she's been with me, and I've been with her all summer long. We're going strong now."
The couple shared a behind-the-scenes look at their holiday photo shoot, which features some adorable outtakes with Zion and Zaire, Wade's two sons with ex-wife Siohvaughn Funches, as well as nephew Dahveon, whom he raises.