John Mayer is rumoured to be jealous of Robert Pattinson.
The Twilight star has been linked to John's ex-girlfriend Katy Perry since reportedly splitting from Kristen Stewart earlier this year.
Now ladies' man John is said to be upset with the actor for quashing any hopes he had of getting back together with Katy.
"When Katy dumped John he tried to put a brave face on things but, inside, he was devastated," a source admitted to British magazine Star.
"He realises their relationship was special and he misses her. He's desperate to win her back. John wishes things could go back to the way they were, but believes Katy's friendship with Rob is getting in the way of a reconciliation."
Katy is said to have helped Rob get through the heartache Kristen caused when she cheated on him with married director Rupert Sanders.
The pals have been spotted hanging out together and recently even crashed a wedding rehearsal together.
"Katy and Rob have been getting close and she has been advising him following his split with Kristen," the insider continued.
"She certainly knows how it feels to go through a rough breakup or two! She never thought it was a good idea for them to get back together."
The source finished by saying John would do "anything" to win Katy back and just wanted Rob "out of the way".
It seems John is doing his best to change Katy's mind by turning the charm on.
The singer was apparently a guest at her Memorial Day barbecue and the two got along famously.
"They seem to be back together - or back together-ish," an onlooker told Us Weekly magazine. "They were very flirty and having a really good time together. They have good chemistry."
Another insider noted “they were definitely friendly” at the bash.
