Jennifer Aniston’s former boyfriend Vince Vaughn is reportedly not happy with her new romance with John Mayer. Sources say Vaughn has warned Aniston that Mayer is “using” her.

“You can’t be serious – this guy is just using you to make a name for himself,” Vaughn allegedly told the actress.

A source says that Aniston “told Vince that in case he didn’t notice, John already had quiet a name for himself, with or without dating her, and if Vince didn’t like the reports that were surfacing, he should stop reading the papers and spare himself a heart attack!”