Breaking Celebrity News has learned exclusively Tiny is on the verge of pulling the plug on her marriage to rapper husband T.I. because she's afraid "he will never stop cheating."

A source close to the 42-year-old mother of four says she's been trying to communicate with T.I. about his infidelity but it "hasn't been so simple," and pals say it appears there's "no way" they can work things out.

"She's secretly talking to lawyers," the informant told Breaking Celebrity News exclusively. "She's sick and tired of seeing him with new women."

The Shade Room recently posted a video of what appears to be T.I. slapping another woman's butt and fondling her breasts as she sat next to him.

The source said seeing the video "really sent Tiny overboard."

"That was a gut wrenching moment. She wanted to take her kids and run," the source claimed.

"She cries herself to sleep and tries to hide her pain from her children but can't. She's at her breaking point."