Mario Lopez Sexy One Night Stand With Pop Star: Find Out Who The 'Extra' Host Had A Vegas Fling With!

Mario Lopez famously had a one night stand with a famous pop star, but wouldn't reveal who it was. Well, we can now tell you who the pop starlet was that Mario bedded!

In his new book Just Between Us, Mario talks about a lot of different topics including his first marriage, his family, and his love life. One of the more titillating stories in the book is the Extra host's Las Vegas romp with a young unnamed singer.

According to Us Weekly, that unnamed pop star is... Britney Spears!

Both celebs were single at the time with Britney divorcing her then-husband, Kevin Federline, and Mario split from his Dancing with the Stars partner Karina Smirnoff.

As MStars News reported, when the Saved by the Bell hunk appeared on The Ellen DeGeneres Show he was very coy about the secret rendezvous.

"I'm trying not to give too much away without giving too much away... it was maybe six or seven years ago... eight years ago?" he said.

Ellen was persistent and asked him if he has interviewed the lady in question since their encounter, but Mario wouldn't budge.

"Out of respect for [my wife] and out of respect for this person, I'm a gentleman, I don't like to drop names, so I don't want to go there," he said.

Then the Emmy winning host started guessing which pop star it could be: Britney Spears, Christina Aguilera, or Celine Dion. Nevertheless, Mario didn't miss a beat and teased "Barbra Streisand!"

Mario later told Ellen the reasons he decided to write the book. His mature outlook on life was definitely a major factor.

"When a man turns 40, it's an important time to pause and reflect on how he got there, and to make a mature plan for the future, and what better way than to write it down?" he said. "People have asked me a bunch of stuff over the years... it's stuff I could really get into in the book as opposed to having the opportunity on TV. When I decided I was going to do something like this, I just said, 'Alright, I'm going to be unfiltered and just put everything out there."

Did you guess it was Britney or are you as shocked as we are?

Watch Mario with Ellen here: