UNHAPPY Holidays

It wasn't a very merry Christmas for these A-listers and their moms

Karen & Mina CLASH OVER CORY

While filming the eighth and final season of their HGTV show, Good Bones, Mina Starsiak Hawk, 36, and mom Karen E. Laine, 61, had a "knockdown, drag-out [fight] during demo," Mina's admitted. Right before Christmas, Mina said on her podcast that she's no longer speaking to co-star Cory Miller. Days later, Karen was accused of betraying her daughter by posting an Instagram photo with Cory! "It felt petty like Mina was stabbed in the back," says a source. "The holidays were miserable."

Mandy & Selena TOXIC RELATIONSHIP

On Thanksgiving, Mandy Teefey, 47, gushed about daughter Selena Gomez, 31, in the wake of the singer's mental health battles, writing on Instagram, "Where we are today is incredible." But behind closed doors, things aren't so rosy. "They've had a tumultuous relationship for years," says a family insider. "Selena thinks Mandy is toxic and told her she has to work on herself if she wants to be in her life."

Cindy & Kaia BATTLE OVER AUSTIN