The boss of Madonna‘s Raising Malawi charity has quit after falling for the star’s ubertrainer, Tracy Anderson.

Executive director Philippe van den Bossche, who helped Madonna adopt her daughter, Mercy, is leaving the charity’s Los Angeles headquarters to live with petite but perfect Anderson in New York.

Super-fit Anderson — who’s credited with honing Madonna’s sculpted body — told Page Six: “Philippe and I have been together for eight months, and things are great. I live wherever Madonna is, so Philippe is moving from LA to New York.”

Anderson and van den Bossche became close during the Material Mom’s trips to Malawi to adopt David Banda and Mercy.

But his departure has left Madonna less than pleased. Van den Bossche told us, “She was disappointed, as it is hard to find the right people to run the projects you deeply care about. But Madonna is a great friend, and she’s happy for Tracy and me.

“It was a hard decision to resign my position at Raising Malawi, but I feel it’s time to concentrate on my relationship and my future, now that I’ve found the right person.”

Anderson, who also trains Gwyneth Paltrow and Molly Sims, revealed how Madonna molds her astonishing body. At Diane von Furstenberg‘s MeatPacking District store during Fashion’s Night Out, she said, “We train for two hours six days a week. We do 45 minutes of dance aerobics, followed by work on muscle tone, flexibility and definition.

“There’s no running and no weights bigger than three pounds, because Madonna doesn’t want to bulk up,” Anderson said.

And she insists that Madge has far better arms than Michelle Obama: “Madonna’s body is perfect. She has no fat, no cellulite, she is so toned, and her arms are amazing. Michelle Obama’s arms look beautiful, but I think I could get her into even better shape.”