JODIE FOSTER’s new love affair is already in deep trouble – because her jealous girlfriend Alexandra Hedison is demanding that the Oscar winner cut ties with her ex.

But Jodie refuses to back down. Her life remains inter­twined with her ex-lover Cydney Bernard, and she told “The L Word” actress Alexandra to get used to it or hit the road, according to a source.

“The honeymoon is over for Jodie and Alex,” declared an insider. The two are butting heads because Jodie and Cydney – who are raising two sons to­gether, Charles, 15, and Kit, 12 – remain extremely close. Just recently, Jodie was photographed helping Cydney move furniture in Santa Monica.

“Jodie and Cydney talk daily and see each other several times a week,” said the source. “They’ve gone from lovers to best friends, and they’ve managed to figure out how to successfully co-parent their sons.”

The two women met on the set of the 1993 movie “Sommersby” and spent 15 years together before their 2008 split. But Jodie, 51, still goes out of her way to praise Cydney, 60, includ­ing gushing that she remains her “heroic co-parent, ex-part­ner in love but righteous soul sister in life” at last January’s Golden Globe Awards.

Sadly, Alexandra, the 44-year-old ex-girlfriend of Ellen DeGeneres, is having trouble adapting to Jodie’s divided attention. “Alex hit the roof after she recently walked in on Jodie and heard her end a phone call with Cydney by saying, ‘I love you, too,’” confided the source.

“Alex grilled Jodie, demanding to know if she was cheating on her with Cydney.

“Jodie was appalled. She told Alex to butt out of her family affairs. She and Cydney talk about everything from their sons’ schoolwork to what’s going on in each other’s love lives, but they are totally platonic.

“Still, the close relationship unnerves Alex. She worries constantly that Jodie is going to dump her and reunite with Cydney.”

POP FYI: Alex is the daughter of actor David Hedison who starred in the film "The Fly" (1958) and 1960s TV series "Voyage to the Bottom of the Sea".