Credit: Todd Williamson/

The first season of The Real Housewives of Beverly Hills ended on a low-note for Kyle Richards.

The 42-year-old mom of four accidentally exposed her sister Kim's drinking problem during an emotionally-charged limo brawl -- a moment she now deems her "biggest regret in life."

"I regret everything about that night," Kyle told Ryan Seacrest on his KIIS-FM radio show Tuesday. "It was terrible. Both of us regret the things that we did and we said. I wish I could take it back."

According to the Bravo star, "there was a lot of stuff happening off-camera. The audience doesn't see everything. I think it came to a boiling point that night and we just kind of snapped."

"We argue now and the and we clash…but that was our first fight ever, no doubt," she continued. "I can guarantee it's the last time we ever fight like that."

Over time, the once inseparable sisters -- whose eldest sibling is Kathy Hilton, mom to Paris and Nicky -- were able to put their differences aside.

"We're good now," Kyle said. "It took awhile, but we're good now. We're in a good place."

Kyle also promised that the second half of the Real Housewives of Beverly Hills reunion special (airing Tuesday at 10 p.m. EST on Bravo) will answer any remaining questions about what transpired that night.

"With these reunions, it's so difficult," she explained. "It's just a chance for all of us to address the things that we've seen on the show with the audience. We don't see what the other girls are taping."