Kyle Richards says that exposing older sister Kim's drinking problem on the season finale of The Real Housewives of Beverly Hills was her "biggest regret in life."

During a fight at castmate Taylor Armstrong's birthday party, Kyle revealed that her sister had been struggling with an alcohol addiction.

"It was terrible," she told Ryan Seacrest on his radio show this morning. "Both of us regret the things that we did and we said. I wish I could take it back."

Kyle, who fought not only with her sister, but with Camille Grammer during the season, went on to say that she and her sister "argue now and then and we clash…but that was our first fight ever, no doubt." But the good news is, "I can guarantee it's the last time we ever fight like that."

When the last episode aired, it was revealed that the sisters had not been talking, but Kyle says, "We're good now. It took awhile, but we're good now. We're in a good place."

The second part of the RHOBH reunion airs tonight.