She informed Davender Singh.
Three weeks later he bled to death in his Honda Torneo on Norman Spencer Drive.
The Crown said when the infidelities were uncovered by their respective partners, the pair plotted to kill the victim so they could be together.
They were unable to call or text anymore because of their spouses' increased scrutiny, so they resorted to secret handwritten notes.
Police found the notes - most of which were written by Kaur - at the workplace and in Gurjinder Singh's car.
The Crown said the messages showed the depth of the passion between the defendants and their commitment to the fatal plot.
"Lali, if everything goes well today do not spare him, he made me suffer a lot really. I do not want to live with him. Love you," one read.
Crown prosecutor Natalie Walker said Kaur concocted or at least exaggerated a story of regular beatings she suffered at the hands of her husband, in a bid to get the support of Gurjinder Singh.
"How would you kill and then after how we would come (back) . . . what do you have that we can use to kill? There is a lot of police around there," another note said.
On the night of the murder, Gurjinder Singh followed Kaur and her husband when he picked her up from work and struck when they pulled over to talk.
Though it was unclear who caused the fatal wound, Ms Walker said it did not matter because both were equally culpable.
However, she said it was most likely Gurjinder Singh wielded the knife while Kaur held her husband in his seat.
While giving evidence throughout the four and a half week trial, Kaur admitted there was a plan to kill but said the day before the murder she had withdrawn from it and reconciled with her husband.
Gurjinder Singh rejected the existence of such a plan and said he turned up at the scene after Kaur had stabbed Davender Singh to death, only taking away evidence when she threatened to blame him.The jury rejected both versions of events.
There was no audible reaction from the dock or public gallery when the verdicts were handed down, but some in the gallery had faint smiles.
Justice Graham Lang convicted the pair of murder and gave them warnings under the three strikes law.
Davender Singh's family have expressed their gratitude after the pair charged with murdering their son, father and brother were found guilty.
In a statement read out by Detective Sergeant Stephen Nightingale outside the High Court in Auckland - the family thanked all those involved in the case.
They said while today's verdict was good news, it would never bring their loved one back and he was greatly missed.
