Khloe Kardashian and Lamar Odom Leading Separate Lives?

Khloe Kardashian and Lamar Odom are living separate lives, PEOPLE reported Monday.

Sources told the publication that the NBA player and reality TV star are no longer on speaking term. The couple, married for nearly four years, have been plagued by rumors of his infidelity and substance abuse issues.  They were described as living apart.

"They're separated for the moment," said the source. "Khloé is spending many nights at her mom's house and Lamar is at his place [in] downtown [L.A.]"

A source said that Kardashian was at a loss over how to help Odom. In 2001, he had admitted to using drugs. She believed that had been in the past and that she "saved him. But in reality she never even knew about his drug issues."

The source added that Kardashian felt she was out of options to offer her assistance to Odom.  The situation was put as a sad one.

"She wants to save her marriage, but Lamar doesn't and he's not in his right mind to do so. So what can Khloé do?" the source said.

Another source said that Odom is the one who wanted to end the marriage. He has allegedly shown no interest in working through the couple's multiple issues.

"I believe Lamar is the one who wants out [of the marriage]. It's not looking good," the source said.