An adult actor and her MMA fighter boyfriend discussed acting out a rape fantasy before he allegedly brutally beat her, ruptured her liver and 18 broken bones, jurors will be told.

Jonathan "War Machine" Koppenhaver is accused of attacking Christine Mackinday — stage name Christy Mack — and a friend at her home after their relationship ended, and faces 35 charges including five of sexual assault and two of attempted murder.

A judge has ruled that jurors will be allowed to hear testimony that Ms Mackinday had asked Mr Koppenhaver to act out a rape fantasy that "never came to fruition" before the beating in August 2014. The couple are also said to have shared a regular joke in which Mr Koppenhaver said, "Real men rape," and Ms Mackinday repeated the phrase back to him, the NY Post reported.

She told a court hearing that the fantasy was a personal “role play” and “fetish” using a “very specific set of guidelines and rules ... for safety reasons and consent reasons".

“I wouldn’t want to have an actual rape happen," she said.

The pair had met in 2013 and Ms Mackinday fell "totally in love with" Mr Koppenhaver, before she said he became abusive "four to five months in".

Ms Mackinday alleges that on 15 August, 2014, Mr Koppenhaver entered her home, beat up her friend and then turned on her. The charges he faces date back to May 2013 and he is already serving a prison sentence for violating probation in an earlier assault case, the Post said.

The 34-year-old's trial is due to begin on 27 February.

Images of Ms Mackinday's injuries shocked social media users when she posted them after the attack. They showed her with eyes swollen shut, a deep bruise on her thigh and shattered teeth.