Is Sophie Monk jealous of Cameron Diaz?

A day after declaring she's "miserable and famous", Sophie Monk admits it's a little hard to watch her ex-boyfriend Benji Madden happy with US actress Cameron Diaz.

The 2DayFM breakfast co-host was quizzed about her love life on Thursday morning by co-hosts Jules Lund and Merrick Watts.

Watts asked: "Benji Madden has upgraded to Cameron Diaz. Are you sad and lonely?"

"No, I mean it's not awesome but it would be better if he dated someone not funny and fat," Monk responded.

Monk was also asked about "kissing" former Australian cricketer Shane Warne, who is believed to be dating model Emily Scott, when in London earlier this year.

"You know you kissed him," Lund said.

Clearly flustered by the line of questioning, Monk was tricked into sharing more than she intended.

"Wait, how do you know that? How do you know I kissed him? How do you know I kissed him," Monk said.

Lund: "You kissed him."

Monk: "I didn't kiss him."

Lund: "Oh, so you're going to lie to a friend?"

Monk: "No, I'm going to lie to the public."

Lund: "I don't know if you kissed him, I'm just making it up, but you just admitted to it."

Clearly embarrassed, Monk described Warne as one of the nicest guys she's met, adding that she's still single.