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Rick Ross has filed for joint custody of the children he shares with ex-girlfriend Briana Camille.

Brianna slapped the rapper with a paternity lawsuit after he stopped paying her child support for their kids, Berkeley and Billion.

Ross, whose real name is William Roberts II, filed a countersuit citing Briana's "erratic behavior", accusing her of preventing him from seeing the children, and also keeping a company car that Ross loaned her.

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Ross seeks joint custody of the children -- a move that will reduce his child support by half.

The rapper was criticized for mocking Briana after a DNA test confirmed he is the father of Berkeley and Billion.

"I can't believe Fat Girl took the blood test, damn, they said she damn near fell running away from them people when they came to make her take the blood test," he said in a video clip posted on May 18.

Ross called Briana his "surrogate" in the caption, writing "Eyez dat baby papi!! My surrogate always delivers!!! Big Thank you #Fatgirl."

Briana is reportedly pregnant with Rick's 5th child. He has two other children, daughter Toie Roberts and son, William Roberts III, from previous relationships.