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Surprise Summertime Ball guest Dev says the JLS boys were amazing.
The 21 year old was blown away by the 75,000 strong crowd, "It was amazing, that was my first time ever doing that."
Dev made two appearances on stage, performing 'She Makes Mr Wanna' with JLS and 'Like a G6' with the Far East Movement
The JLS boys certainly made an impression on Dev, "They melted my heart."
Dev went on to add, "Mann is a good friend of mine, I see him all the time and do a lot of concerts together" and she expressed an interest in collaborating with Mike Posner, "I am a big fan of him. I'm a big fan of his beard".