A Sydney man was fatally stabbed by his mother-in-law after repeatedly attacking her and accusing his wife of having an affair with her taekwondo teacher.
The inquest into Adam Coble's death in his North Richmond home in January 14, 2019, found it followed a violent fight between him and his wife Robyn, and her mother Kay Leonard.
The evening before Ms Coble had returned home highly intoxicated following a meeting with a man, and Mr Coble helped her to bed before scrolling through her mobile phone.
The successful upholsterer spied sexually explicit text messages between his wife of 19 years and her martial arts instructor and made a number of abusive comments that evening, but she didn't respond.
The following morning he removed his wedding ring and cut it with pliers declaring: "That's what you did to my heart".
The couple continued to fight before she phoned her mother who went to the home and told Mr Coble to move out and stay with his mother if they could not stop arguing.
This prompted him to retrieve a knife from the kitchen before grabbing Ms Leonard's hair from behind and pushing her face onto the ground.
He then stabbed her in the neck and continued as Ms Coble yelled: "You're killing my mother," according to her mother's written statement.
Ms Coble attempted to restrain her husband and placed him in a headlock hold forcing the pair backwards, while Ms Leonard says she told her not to let go "or we would all be dead".
While on her back Ms Leonard wrangled the knife from Mr Coble with a sweeping motion plunged it into his chest.
Detectives soon arrived and pronounced him dead at the scene.
Wounds sustained by both women, including a number of cuts to Ms Leonard's forearm and hands, were later examined and found to be consistent with their version of events.
Despite Mr Coble's family raising the possibility of premeditation, the inquest found no evidence of this.
"This episode of interpersonal violence ... was spontaneous in nature, having escalated from a verbal argument between Adam and Robyn," coroner Derek Lee said.
Before their deadly fight, the couple's marriage was described as volatile, strained, and "off and on".
Both frequently consumed excessive amounts of alcohol which often led to arguments and the deterioration of their relationship, while a number of verbal domestic violence incidents were reported to police.
But from 2018 these escalated to physical fights and property damage, and an AVO was taken out against Mr Coble on behalf of his wife.
In December 2018 the couple had abstained from alcohol and were undertaking counselling for their substance abuse issues.