When Christie Lee Kennedy saw her husband kissing another woman she felt her "whole life had been torn apart".
But the 37-year-old has denied deliberately driving into her cheating spouse and his mistress just seconds later.
Kennedy had been married to David Larkin for almost a decade when she discovered he was having an affair with Zowie Noring in March 2021.
The mother-of-two is accused of intentionally running over Mr Larkin and Ms Noring in her BMW SUV after discovering them together at Wavell Heights in Brisbane's north.
Kennedy also got out of her car, grabbed Ms Noring by the hair and repeatedly punched her while screaming obscenities, the District Court has heard.
Kennedy said her plan was simply to find out what her husband was doing when she discovered he was visiting a park she didn't recognise for the third time that week.
When Kennedy approached the park in her car she saw her husband "kissing, groping and cuddling" Ms Noring.
"I couldn't believe what I was seeing. Basically my whole life had been torn apart," a teary Kennedy told the court.
Kennedy said she abandoned her plan to "hide and have a look" because she was quickly spotted by her husband and Ms Noring.
Instead she decided to accelerate down the street in a bid to "catch him out".
"Then (I) realised oh my God ... I remember hitting on the brakes, trying to stop (but) I already hit them," she said.
"There was no way I intended to hit either one of them."
Kennedy said she exited her car in a state of shock.
"I was shaking. I was about to collapse. I yelled something at her ... and I think I punched her a couple of times but I was that in shock, in disbelief and shaking," she said.
"I was just not expecting to find what I did."
Kennedy said she thought she had a perfect marriage before the incident.
But she first became suspicious when Mr Larkin began telling her he would leave work early for a childcare pick-up.
"That was really unusual for him because he would normally put in big hours," Kennedy said.
When she rang to check if the children had been collected Mr Larkin's phone was either switched off or rang out, she said.
Concerned, Kennedy looked at a phone locator app and discovered Mr Larkin was at a park she had "no idea about".
"I mentioned to (a friend) ... that Dave was attending this park ... and she said 'that is near Zowie's work'," Kennedy said.
Her friend then told her Ms Noring had been talking to Mr Larkin on a messaging app.
"I said 'anything going on between David and Zowie' ... and she said 'oh no, I doubt it'," Kennedy said.
She said according to the phone locator app Mr Larkin visited the park twice in three days.
When it occurred a third time, Kennedy decided to drive to the location despite assurances from her husband the night before that "everything was OK".
She intended to go there, hide, have a look, then return to work and talk to her husband later that night about it, she said.
Kennedy has pleaded not guilty to two counts of malicious acts with intent to disable.
She has pleaded guilty to unlawful assault.
The trial before Judge Tony Moynihan continues.
