Katy Perry was beginning to develop feelings for John Mayer.

The 'Firework' singer's two-month fling with the long-haired lothario ended last week and she was allegedly hurt'' and ''really upset'' he called things off because she was hoping for a relationship.

A source told Us Weekly magazine: ''They weren't serious, but she was really starting to fall for him. She wasn't seeing forever with him, but saw it lasting longer than it did.

''Katy likes the 'new' part of a relationship, when everything's exciting and you're getting to know the guy. So she wanted to continue experiencing that with John.''

Despite their romance coming to an end, Katy - whose divorce from Russell Brand was finalised in June - wants to stay on good terms with the singer.

The source continued: ''There isn't any emotional baggage with them. They may go out again, even, just as friends.''

John - who has infamously dated Jessica Simpson, Taylor Swift and Jennifer Aniston - appears to have swiftly moved on and was seen flirting with several women last Thursday night (23.08.12) at the Soho House in West Hollywood.