Jennifer Aniston’s friends fear that her blossoming romance with John Mayer will end in heartbreak – because he’s just not that into her.

Whilst the 39-year-old former Friends star is looking for a serious relationship, serial-dater Mayer, 30, is just after a “summer fling” say her pals.

“John says that Jen and he have a physical connection as deep as their spiritual one,” one tells OK!.

“But he also said he’s categorizing this as a summer fling for now.”

The friend adds that the singer/songwriter - who has been linked to Jessica Simpson, Cameron Diaz and, most recently, Minka Kelly - has “never been faithful to anyone.”

Do you think Mayer's intentions are honourable given his track-record? Be sure to let us know your thoughts!