Kroy Biermann Worried Kim Zolciak Will Talk Divorce on 'Real Housewives ATL'

Kroy Biermann knows his estranged wife, Kim Zolciak, has zero filter when it comes to talking drama on camera, and he's worried about how it might impact their children.

According to new legal docs, obtained by TMZ, the former NFL star filed a motion to appoint a guardians ad litem -- meaning someone who would essentially make sure the best interests of the kids are represented during the divorce proceedings.

Kroy claims he's tried his best to keep the estranged couple's minor kids -- Kroy Jr., Kash, and twins Kaia and Kane -- away from all the noise Kim's been making about their split, but adds she's constantly dragging him and talking in an "abusive" and "derogatory tone" about the divorce.

He's also concerned Kim will use her 'Real Housewives of Atlanta' outlet to garner more attention ... noting she's already alleged he smokes too much pot to take care of the kids, something he insists she has no proof to support.

Kroy doesn't hold back -- saying she's the one who's not paying enough attention to their kids lately and has been spending too much time on virtual slot machines ... adding one of the few times she does pay attention is when she lets them gamble on her account.

What's more, he says he's concerned she's taking videos of herself while driving with the kids in the car, and says he's picked up most of the slack since they let go of their nannies and chefs ... although he does say Kim has made a few meals for the kids like chicken fingers and frozen pizza.

TMZ broke the story, Kim recently posted a pic of herself with some 'RHOA' cast members -- leading many to speculate she was back to filming on the show. However, our sources say the photo was taken a few months back -- before the split -- and Kim only filmed a cameo.