Justin reduces Britney to tears

The 21-year-old was in the middle of talking about the “tough year” she has had: criticised in London by showing up late to a film premiere and refusing autographs and booed in Mexico when she walked off stage when it began raining during an open air concert.

But it was when she was asked about Timberlake that the tears began to flow.

“It was pretty rough. Yeah. Yeah, it was kind of weird. Weird. Hello. Um, oh my goodness” she said before breaking down.

She recovered to say she had believed she and Timberlake had a relationship that would last a lifetime. She and the 22-year-old singer were together for three years until their break-up.

“You know, I mean, I, you don’t go around sleeping around with people,” Spears said. “I mean, I really thought that I was gonna be with him or the rest of my life. I did.”

When Sawyer asked Spears if she could think of an instance when she has gone further than she wished she had, Spears said “No. I don’t think so.”

But when she looked at a photo from a recent Esquire magazine photo shoot - where she took everything off but her pearls, underwear and shoes – her reaction changed a little.

“Now, those are a little much,” Spears said adding it is moment she wishes she could reconsider.

When asked about her voice, she surprisingly revealed envy for pop rival Christina Aguilera.

“I would love to have a voice like Christina. I would love to have a voice like Whitney Houston,” she said.

Spears, who was once famous for her virgin status, said she now believes that waiting until marriage could be an unrealistic goal for long-time couples, but casual sex is still a no-no.

“I think in reality, if you really know in your heart of heart that you are gonna be with that person, forever, and you really think that, with all of your heart, and you’re in four, or five years, you know, into the relationship, I mean, stuff can happen,” Spears said.