Watch ET's Tuesday 'Beverly Hills, 90210' Web Exclusive! Online

It's Tuesday, so get ready for ETonline's fifth exclusive "Beverly Hills, 90210" clip as we countdown the days until the September 2nd premiere of The CW's new "90210" spin-off. If it looks like a duck and walks like a duck: It's not exactly a catfight, but harsh words are spoken when Brenda (Shannen Doherty) discovers Kelly (Jennie Garth) is dating Brenda's ex, Dylan (Luke Perry) in the "Rebel With a Cause" episode from season three. Brenda's date, Rick (Dean Cain in pre-"Lois & Clark" days) tries to mediate between the ladies, but then Brenda goes too far and ... well watch the video and find out! Before the launch of the new series, SOAPnet will celebrate the original Aaron Spelling show with a 24-hour marathon, starting at midnight on Monday, Sept. 1 -- with ETonline giving you a sneak peek of the episodes that will air!