In 2013, Leah Remini left Scientology and began publicly speaking out against it, giving lengthy interviews and eventually creating a docu-series, Leah Remini: Scientology and Aftermath. The process burned a few bridges, especially the bridge to Kirstie Alley, who spoke to Howard Stern in 2013. "When you are generalizing, and when your goal is to malign ... when you decide to blanket statement, 'Scientology is evil,' you are my enemy," Alley explained (via The Huffington Post). She went on to say, "She's a bigot. If someone was out there [attacking your religion], would they be your friend? They wouldn't be mine ... I just won't have people in my life that are [bigots]."

Remini described her period exiting the church as "devasting," telling Buzzfeed she spent a lot of time "hysterically crying" as people she thought were her friends "abandoned her." "They only cared that their lives would be disrupted if they stood with me," Remini said. "They didn't care about doing the right thing. That showed me that everything the church taught me was a lie." In 2018, Alley seemingly implied on Twitter that Remini had something to do with an alleged assault of her co-host Mike Rinder's wife. Remini shot back at Alley, saying she had "no balls on top of no integrity," adding, "You're spreading false/defamatory info at the demand of your cult." 

All that being said, it doesn't seem like these two are likely to patch things up any time soon.