Dwyane Wade and Gabrielle Union
01/28/2014 at 04:30 PM EST
The couple that sings together, stays together.
and fiancé Dwyane Wade
sang karaoke for a cause Monday at South Beach Battioke at the Fillmore Miami Beach, which benefitted Shane Battier's Take Charge Foundation.
Union strutted her stuff to "I've Got Friends in Low Places" while reigning NBA MVP LeBron James sang "Back That A–– Up" and brought the house down when he, Wade, and Udonis Haslem grooved to Robin Thicke's "Blurred Lines." The Hangover
star Ken Jeong also made an appearance with a convincing Guns N Roses rendition.
Prior to showing off her country side on stage, Union opened up to PEOPLE about the overwhelming support she's received since announcing her engagement.
"For everyone who's kind of given up, and is maybe a little older and it's the second time around, I think everyone kind of feels like it's their wedding and we're all in this together," she explained.
Of the twosome's wedding plans, the Being Mary Jane
star joked, "He's in charge. I'll just get a save the date and ... see what happens."
Happily engaged since December, Union said she is still able to relate to her character's questionable relationship judgement saying, "I'm divorced, so I've made a ton of bad decisions in relationships."
– Becky Randel