Union, 43, told Ocean Drive magazine for its May/June cover story that her stepchildren were the "driving force" behind the actress's 2014 nuptials to the NBA star.
"D and I could have gone on for a long time as boyfriend and girlfriend, but the kids were the driving force in wanting us to be a legitimate, like, real – and I'm using my finger quotes – family in their eyes," she said. "We got on board with it, and it's the best decision we could have made – not just for us as a couple, but for our family."
Wade, 34, has three sons: Zaire Blessing, 13, Zion Malachi Airamis, 8, Xavier Zechariah, 2. He also raises his teenage nephew, Dahveon.
Courtesy of Ocean Drive Magazine
Nearly two years into the marriage, Union said the couple couldn't be happier. She credits their successful relationship to their strong bond and ability to talk things through.
"If you have good, effective, honest communication, you can handle any issue or problem in a relationship," she said. "We really, really enjoy spending time with each other more than anybody else. Well, with D, maybe I’m tied with LeBron! But I'm definitely his favorite female! If you have the chance to marry your best friend, I would highly recommend it."
So who is the disciplinarian of the household?
"We literally keep track," she said. "There's basically an imaginary chart: 'I was bad cop last time; now it's your turn. You have to be the jerk who doles out punishment for missed homework assignments or talking on the phone after curfew."
But laying down the law from time to time hasn't stopped the boys from feeling comfortable enough to come to Union with any problems or advice – especially when they want something.
"With the older boys, they come to me with girl stuff, homework. Or if they're trying to butter up dad, they definitely come to me to soften me up first," she said. "I'm the line of defense I guess, before dad."