In Thursday's season finale, Kim and Kyle got into a drunken fight at Taylor Armstrong's birthday. Following an initial argument between Kim and Armstrong, Kyle and Kim went back to their limo where the sisters fought some more.
"You are a liar," Kyle said, claiming that her husband sends Kim money every month. "You are an alcoholic! Yeah, that's right. I've said it now, and everybody knows." Kim then stormed off, telling her sister that she's on her own.
At the close of Thursday's finale, which garnered a series high 4.2 million viewers, a banner on the screen announced that Richards had been checked into rehab by her family, and that Kim and Kyle have not spoken since the fight. A week later, she checked herself out.
"My heart was broken and I suffered an incredible amount of anxiety and panic attacks," Kyle later wrote on the Bravo blog. "Next to losing my mother, this was the most difficult time of my life."