Which Hollywood actress had a secret affair with Diddy?

In a new interview with Playboy, Diddy (P Diddy/Puff Daddy/Sean Combs or whatever he's calling himself these days) talks himself up as some kind of sexual god who no woman can satisfy.

No surprises there, but among several big-man claims (he tried to lose his virginity at age seven, he's trained himself to go for up to 30 hours) he says he had a secret affair with a top Hollywood actress that could have "shaken up the world" if the news had got out.

"Yeah, there was a young lady who’s an actress," reveals Diddy. "She’s famous. I liked her, so I was willing to do whatever I had to do. I told her, 'I will sneak up the side of the building to see you.' I was persistent.

"We started spending time together, but we were prisoners of our celebrity. She took me to dinner after we got to know each other and hit me with a line that was straight out of the movies. She said, “You know this will never work, right?” [laughs] I knew she was right."

But when the interviewer pressed for a name, Diddy wouldn't spill.

"The only person I’m gonna tell is God. If he says I can’t get into heaven I may whisper it in his ear. She was so cool the way she let me down softly, and she offered me a ride back to my hotel."

When Sienna Miller's name was put up for suggestion, Diddy was quick to deny it — and hint that it was someone far more famous.

"I can clear that up right now. It wasn’t her. This was going to shake up the world. It would have been a Puff and J. Lo situation, part two."

Could it have been Cameron Diaz? The pair were spotted together a few times in the past year.

Who do you think it might have been?