Mary J. Blige and Kendu Isaacs’s split has been a nasty one. Just a few days ago, it was reported that the singer claimed her estranged husband spent her money on his new girlfriend. Now, it’s being rumored that the new girlfriend isn’t so new.

According to Page Six, that girlfriend was a former protégé of Mary J’s and was likely the cause of the couple’s split. Sources told the website that Isaacs cheated on Blige with Starshell, a 28-year-old up-and-coming artist Blige signed to her Matriarch Entertainment record label.

“Everyone knew. Mary was the last to know, but it’s like, how do you not know?” the source says. “It’s really f**ked up and low to have it done to her that way. Had it not been for Mary signing her, investing time and money . . . Because no one cared about her music.”

Another source says Mary had her suspicions but was more blinded by love.

“It was more like one of those things where you end up believing what you want to believe,” they said. “But Mary had her suspicions.”  

Blige recently filed documents in court over her divorce of Issacs. Not only is she not happy about the split, but says Isaacs, who was also her former manager, spent more than $420,000 on “travel charges.” Pretty ambiguous, and probably for good reason. Blige claims those expenses were not business related and, in fact, was money Isaacs spent on his side chick.

Previously, Kendu Isaacs requested more than $110,000 per month in spousal support, which Mary J. scoffed at. She doesn’t believe she should be responsible for her ex’s parents and children from another relationship.