Lindsay Lohan and her former girlfriend Samantha Ronson have officially hit an impasse in their often-troubled relationship, according to a PEOPLE source.

“Sam let Lindsay back into her life as a friend, but now even a friendship seems impossible,” a Ronson insider tells PEOPLE this week. “No matter how many times she promises to change, Lindsay loses control and starts acting like a maniac.”

The confidential informant adds that despite being photographed together in recent weeks, Lindsay and Samantha never rekindled their romantic relationship, which

“She is telling everyone that Sam dumped her again, but it makes no sense since they never got back together.”