With rumors about Brandon Blackstock cheating on his wife, and former "American Idol" star Kelly Clarkson, the singer is now convinced of the cheating after fighting for her husband on Twitter.

Initially Clarkson was in disbelief about the cheating allegations, but now she is planning to leave Blackstock because of his infidelity.

The "Wrapped In Red" singer tweeted defending Brandon and calling the allegations "lies." She was also concerned that Brandon's kids, to whom Clarkson is a stepmother, would be affected by the stories on social media.

Blackstock's ex wife Melissa Ashworth endorsed Brandon and Kelly's marriage, saying that the cheating rumors are ridiculous. Blackstock himself took Twitter to garner his innocence, "It's sad how low life's make up rumors about @Blackstock."

Reports said that an anonymous woman "spilled the beans" on Blackstock: “We haven’t slept together,” she claimed on tasteofcountry.com. “But we’eve been intimate in other ways. I really hope his wife keeps her eye on him because he’s not the great man she thinks he is.”

In the same week, another woman said that Blackstock had a one night stand with her, and that she is pregnant with his baby, according to the Daily Mail.

Oddly, a family friend accused Blackstock of cheating on his former wife Ashworth, but she denied the allegations. She claimed that the music manager and stepson of Reeba McEntyre has always been a model partner.

Blackstock and Clarkson are expecting a baby, and Clarkson said she will divorce Blackstock after their baby is born.

"Clarkson, meanwhile, postponed the overseas promotional tour for her new Christmas album, “Wrapped In Red,” claiming to be “incredibly ill” from her pregnancy," said a report from RadarOnline.