Well now we know why LC won’t be in the house when Heidi and Spencer exchange vows this weekend.

Lauren Conrad always believed that Spencer Pratt and Heidi Montag were behind a rumor claiming she had recorded herself having sex with former bad boy BF Jason Wahler, but the pair consistently denied any involvement in the scandalous act –until now, that is.

At The Hills Panel at PaleyFest09 in Los Angeles on Tuesday, Lauren Conrad revealed that Spencer Pratt, the fiance of her ex-BFF, Heidi Montag, recently admitted that he did in fact start the rumor that she recorded an intimate video.

Lauren revealed the news after the panel moderator asked if she still thought Heidi and Spencer were to blame for the rumors.

“We actually have it on tape,” Lauren told packed audience. “[Spencer] takes responsibility and apologizes for it.”

“Sorry! Spoiler!” Lauren laughed.

Whispers of the sex tape, which does not exist, first surfaced after shooting wrapped on the second season of The Hills two years ago. The rumor ended the friendship between Lauren and Heidi and sparked the still on-going feud between the women.

In fact, Heidi once accused Brody Jenner of starting the sex tape rumors. And if his comments on Tuesday are any indication, BJ’s still pretty broken up about that.

“They knew they had spread the rumors…They were plotting and scheming to point the fingers at everybody else when everybody knew it was them who did it. There was no way of getting out of it. I think that was their desperate measure of trying to get out of it.”