Photo: Getty Images

By Kathleen Perricone

Jason Priestley is reliving his hey days in his new book, Jason Priestley: A Memoir.

And the former Beverly Hills 90210 star called in to On Air with Ryan Seacrest on Monday morning to dish on all the gossip that went down before he was famous … like the fact that he used to be roommates with none other than Brad Pitt!

One of the things they used to do for “fun”? Seeing who could go the longest without showering!

“This is back in the ’80s … this was before we has the Internet or smartphones in our hands. We had to come up with ways to entertain ourselves! … Brad always won.”

Another big star Jason hung around with before he was famous was Holly Robinson Peete, who he dated when she was on 21 Jump Street.

And because he wasn’t famous yet, the actress usually got stuck with the bill. But once Jason started making money, he paid her back even though they had broken up. ”My parents raised me up right,” says Jason. “I was a young, honorable guy … I kept a tab of what I owed her. It’s the right thing to do, right?”

For more from Jason, like bouncing back from his 2002 car accident that left him in the hospital for three months, listen to the audio above.

Jason Priestley: A Memoir is in stores now!