According to Rita, 23, the Scottish DJ, 30, never okayed the performance of the chart-climbing single I Will Never Let You Down.
"For anybody who doesn't understand how it works, he wrote and produced the song," she revealed on On Air with Ryan Seacrest. "So he has to approve anything TV-wise for anybody who doesn't get it. And obviously he owns the rights to it and he didn't approve the Teen Choice Awards."
The two ended their relationship in June, but Rita told Ryan that although "people move on and move forward" the message of the song remains.
"It was the first time I ever kind of opened my doors up for somebody I knew personally," said Rita. "So, this song was written out of love and I [liked it], it was convenient for the time it was written."
When asked if she was caught off guard by Calvin's move, she said that she was not surprised.
"I could have got told a few weeks earlier," said Rita. "That would have been nice. It was a last minute change, but you know what, it happens and we move on and move forward ... It is what it is, man. You know, you write a song with somebody, and I guess there's some stuff that comes with it ... Everything happens for a reason, that's how I look at it."