OUCH! Rita Ora confirms On Air with Ryan Seacrest that Calvin Harris actually DENIED her to perform his song at the Teen Choice Awards.  

During the interview Rita mentioned, "Unfortunately we couldn't do the Teen Choice Awards," and when Ryan asked why she simply said, "Ask Calvin" before diving into the dirty details. 

Ex-boyfriend Calvin Harris wrote and produced her hit single "I Will Never Let You Down," and because he did he had to give permission for her to perform the song on TV... in which he DENIED the performance to happen.

And Calvin Harris has fired back at his ex with this Tweets: 

Watch the interview below: