Britney Spears Ex-Husband Kevin Federline Claims She Cheated On Him With A Female Dancer

Britney Spears' ex-husband and father of her kids, Kevin Federline (remember him?), has a new book called You Thought You Knew. You know, now that the couple's two sons are all grown up, it's time to tell some of those never before told stories about their mom.

Like the time that K-Fed and Britney had their first fight. He claims that it happened after he caught the singer cheating on him with a female dancer in a hotel room on tour in Amsterdam, according to an excerpt from the book that USA Today got their hands on.

Pop superstar Britney Spears and Kevin Federline spend time together in Amsterdam on May 6, 2004 in The Netherlands. (Photo by Dennis van Tellingen/ISP/BSR Agency/Getty Images)

That's a story that I'm sure the kids are going to love hearing all about, if they haven’t already been briefed on that first fight between mom and dad.

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"Britney and I went to our room, but shortly after, she said she’d be right back. At first, I didn’t think much of it. The hotel floor was ours; they had booked it out for the entire tour, so everyone’s rooms were nearby. But as time passed, I began to wonder what was taking so long," K-Fed wrote.

"Eventually, I decided to check if everything was okay. I stepped into the hallway, our door still cracked, like most on the floor, and headed toward the elevators. As I passed one of the rooms, I glanced inside – and froze. There she was. Theresa was sitting on the edge of the bed. Britney stood between her legs, hands on her face, and they were (expletive) going at it. Full-on making out. It was one of those moments that hits you so fast, your brain can’t even begin to process it."

Singer Britney Spears during the residency show Britney: Piece of Me at The AXIS auditorium located in the Planet Hollywood Resort & Casino. Las Vegas. (Photo by Marco PiracciniArchivio Marco PiracciniMondadori via Getty Images)

What Happened After K-Fed Says He Caught Britney in the Act

Federline was stunned, he couldn’t believe it was real. He watched before they both noticed he was there and that's when he stormed off and started packing his suitcase. He said, "At that point, I cared about nothing else – I just wanted out."

And that's how he became the first man in all of recorded history to get upset at the site of the woman he loved with another woman. I mean that was the start of the couple's first fight.

K-Fed said he wanted to leave and end things with Britney, but she begged him to stay, which he of course did. That decision to stay, he says, "laid the foundation of our relationship."

Singer Britney Spears during the residency show Britney: Piece of Me at The AXIS auditorium located in the Planet Hollywood Resort & Casino in Las Vegas. (Photo by Marco PiracciniArchivio Marco PiracciniMondadori via Getty Images)

He added, "It was during this time that I began to realize the depth of my feelings. And while the road ahead was anything but certain, I knew one thing for sure: I was falling in love with Britney."

How could he not fall in love with Britney Spears? What's not to love?

She was one of the biggest stars in the world. She was hot, and she was willing to spend some time in a female dancer's room from time to time.