The actress joked to E! News that the already embarrassing sex scene was made worse by director Bill Condon's attempts to micromanage both herself and Pattinson.
"Bill kept saying that he wanted to make this one feel like you're very much inside of the experience," she recalled. "Like you're there, you're sort of a part of it, which is odd. But to do that we had to look directly into the camera instead of at each other."
Stewart added that the result was a powerful scene for Breaking Dawn - Part 2, but an uncomfortable personal "experience".
"It was awful," the star quipped. "It was like, 'Bill, you're depriving me of this experience. We've been waiting for vampire sex! What are you doing?'"
Pattinson also recently made light of the Twilight Saga: Breaking Dawn - Part 2 sex scene by describing it as "ridiculous".
> Twilight: Breaking Dawn: Kristen Stewart opens up on Bella's journey
The Twilight Saga: Breaking Dawn - Part 2 will be released on November 16. Watch a trailer below: