Michelle Obama confronted a pro-gay rights heckler yesterday at a Democratic party fundraiser, telling her: "You can take the mic but I'm leaving."
The heckler was demanding an executive order from the Obama's husband, President Barack Obama, on protection from employer discrimination.
According to the The Huffington Post, the First Lady said: "One of the things I don't do well is this," to loud applause.
She then walked away from the lectern and towards the heckler, saying she could: "listen to me or you can take the mic, but I'm leaving. You all decide. You have one choice."'
The crowd reportedly shouted that they wanted her to stay, and for the heckler, later revealed as 56-year-old Ellen Sturtz, to go.
Ms Sturtz was then escorted from the room, saying in an interview later: "She came right down in my face. I was taken aback."
She said she had paid $500 to attend the event as part of a plan by the gay rights group GetEqual. The event, held at the upmarket Washington home of a wealthy lesbian couple, saw 200 Democrat supporters pay up to $10,000 to attend.
President Barack Obama came out in favour of gay marriage last year during his re-election campaign and has been even more vocal in favour of equal rights since his second term began.
The official White House transcript of the event omitted the First Lady's reported threat to leave the event if she was further interrupted.
In a statement afterwards, Ms Sturtz said: "I lived and worked in the closet, hiding who I was in order to earn a living.
"I had planned to speak tonight with DNC (Democratic National Committee) officials but, as the First Lady was talking about our children's future and ensuring that they have everything they need to live happy and productive lives, I simply couldn't stay silent any longer.
"I'm looking ahead at a generation of young people who could live full, honest, and open lives with the stroke of the President's pen."
A few hours before the heckling incident, White House Press Secretary Jay Carney told reporters: "I can tell you that the President has long supported, as you know, an inclusive Employment Non-Discrimination Act. ... And his administration will continue to work to build support for it.
"The President's record on support for LGBT rights is significant and well known."