Calvin Harris and Nicole Scherzinger are ''casual friends''.

Although the pair were spotted partying together in London over the weekend insiders insist they are not dating as Nicole, 38, is still seeing tennis ace Grigor Dimitrov.

A source told E! News: ''They're casual friends, and if they see each other at a club or party they will chill. They are not hooking up or hanging out. Calvin isn't rebounding with anyone at this time.''

Calvin, 32, split from Taylor Swift, 25, in May after 15 months of dating and she quickly moved on to Tom Hiddleston, leaving the DJ ''hurt''.

A source told the New York Post newspaper's Page Six column: ''He's not happy about their relationship. He was hurt. Looking back, some friends do feel like Taylor's team manipulated and orchestrated part of [her] relationship [with Calvin] after seeing how public she is with her new guy. It makes sense.''

Although Calvin has previously claimed the break-up was ''amicable'', he later deleted all pictures of Taylor from his social media accounts after her romance with Tom was revealed.

And it has been claimed that Taylor thinks she is ''in love'' with Tom.

A source said: ''She is having a blast travelling with him. He is very romantic and attentive towards her. He is extremely charming. He also makes sure she feels safe wherever they go together.

''She is on cloud nine and really enjoying this quality time they are spending. She texted her close friends and said, 'I think I am in love and I never felt this way before!'''