Drew Barrymore is begging bestie Jennifer Aniston to dump commitment-phobic rock star John Mayer, telling the unlucky in love 40-year-old: “You can do better!” The National Enquirer claims.

In case you didn’t know, Drew’s status as a two-time divorcee qualifies her as a relationship guru.

The beauties became close after co-starring in the romantic comedy He’s Just Not That Into You.

Drew is urging Jen to boot Mayer because she is convinced the “Clarity” star is simply using Aniston to further his career.

According to an Enquirer source:

“Drew told Jen she could do way better and she’d be a fool to settle for him. The first time Jen introduced twice-divorced Drew to John, they clashed.”

The insider adds, “They bickered for so long that Jen had to step in and change the subject. And even though Jen is crazy in love with John, I think a part of her is worried that Drew may be right.”