Mayer will 'break Aniston's heart'

A friend of John Mayer thinks his relationship with Jennifer Aniston will end in heartbreak.

Mayer, who Aniston reportedly rates as a better lover than Brad Pitt, could soon "move on to the next girl", according to Hot Stars.

"He'll spend every waking minute talking to someone and spending time with them and then move on to the next girl," a friend of the musician explained.

Jessica Simpson, who split with Mayer last summer, also thinks Aniston should be aware of his "ladies's man" reputation.

"Jessica wants Jen to be aware of what she’s letting herself get into with John. She doesn't want her to make the same mistakes. John is a ladies' man," a source said.