After Joe Jonas and Sophie Turner got divorced, their friends are worried that their fight could go on for a very long time.

Since Jonas filed for divorce from the Game of Thrones star last month, the two have been in and out of court.

After a few weeks, Turner sued the singer for keeping their two girls, Willa, 3, and Delphine, 1, in the U.S. without a good reason.

An insider said that the star felt “she had no other choice but to sue and get the court involved.”

Turner also gave a letter from the Jonas Brothers star to the owner of an estate in the U.K. as proof that they plan to move there forever.

The Sucker singer, on the other hand, kept their girls’ passports away from the Do Revenge actress so she couldn’t move.

“Sophie doesn’t even know who Joe is anymore,” the person said.

“Nobody thought things would get this nasty between Joe and Sophie,” they said, adding that their friends are telling them to “mature for the sake of the kids.”

Friends think it’s clear that “neither one is going to acquiesce to the other,” which means the fight will “go on for a very long time,” as the source said.