A source said: ''They like each other Katy and DJ Diplo are casually dating, but she's developed a huge crush on Harry, which she calls unexpected. He looks up to Katy and loves that she isn't your typical needy twenty-something.''
Harry, 20, reached out to offer the 29-year-old beauty advice following her apparent falling out with his ex-girlfriend Taylor Swift, after the country star gave an interview and spoke about a ''straight-up enemy'' widely assumed to be Katy.
But the source also told the UK's LOOK magazine: ''I think he's concerned Katy's playing him to get back at Taylor for supposedly bad-mouthing her."
Taylor is said to be ''shocked'' by the pair's closeness. A source said: ''She's shocked. Katy dating an ex? Yeah, that would hurt.''
