Jennifer Hudson and President Obama
01/23/2014 at 12:15 PM EST
Even the commander in chief likes to cut a rug, occasionally.
"Oh, [President] Obama, he's got this one little move. I was like, I've got to watch this so I can imitate this move!" Jennifer Hudson
told PEOPLE of the scene at First Lady Michelle Obama
's 50th birthday party
"They loved it. They enjoyed themselves, that's for sure," the Grammy and Oscar winner added.
The American Idol
alum, 32, who caught up with PEOPLE at Carnival Cruise Lines' Carnival LIVE Concert Series launch on Wednesday, famously serenaded the president on his own 50th birthday in 2011. But on Saturday, she had the night off.
"Everyone thought I was singing, and I walked around the entire party the whole night like, 'No, I'm not singing! I'm not singing!' " Hudson said.
Instead, she spent the night mingling with politicians and celebrities. Her highlights: meeting fashion designer Donna Karan for the first time, and cheering on John Legend, Ledisi and friend/Dreamgirls
, all of whom did perform.
"I'm a huge fan of all three of them," Hudson said. "I've never seen Beyoncé perform in more of an intimate setting, which was the coolest thing to see."
Did Hudson have a present for the president's wife? "No, because the White House is not easy to get into. I was thinking, 'Will my gift even make it through the door?' " Hudson says.
"Just being there to celebrate her, I think that's pretty much the best way you can celebrate someone like that ... It was a blast."