An Australian court has heard an audio recording of an "intense altercation" between Gable Tostee and New Zealand tourist Warreina Wright.
Tostee pleaded not guilty to murdering Ms Wright early on August 8, 2014, and is now standing trial in the Supreme Court in Brisbane.
Ms Wright's mother Beth was emotional during the trial, bursting into tears when Tostee entered his plea and putting her head in her hands as she heard the prosecution's description of how scared her daughter was.
Twenty-two witnesses are due to give evidence in the case.
The prosecution alleges Tostee threatened and intimidated Ms Wright, causing her death, which he denies.
Prosecutor Glenn Cash told the jury Tostee forced Ms Wright onto the balcony of his Surfers Paradise unit, locking the door into the flat.
It left Ms Wright feeling her "only means of escape" was to try and climb down the exterior of the building.
Ms Wright fell to her death from the 14th floor balcony of the Avalon Apartments unit complex.
"You're lucky I haven't chucked you off my balcony, you psycho little b****," the court heard Tostee told Ms Wright.
A woman who lived directly below Tostee gave evidence in the court, saying she heard a woman yell "no, no, no", before seeing two legs dangling over his balcony.
The court was shown a reconstructed image of that moment (Newshub.)
Tostee's defence team says Ms Wright became increasingly erratic before she fell to her death, and that she repeatedly struck Tostee.
In the audio recording Tostee is heard saying: "I said you didn't have to leave, I just said stop beating me up," to which Ms Wright responded, "Are you going to untie me?"
Ms Wright threatened to break Tostee's jaw and call the police if he didn't untie her.
The pair can be heard arguing in the recording, with Tostee saying: "I don't deserve this sh**, I'm a nice f****** guy," and later saying: "I'm the most tolerant person in the world."
More of the audio recording is expected to be played when court resumes on Tuesday.