A man was murdered on his own doorstep after a row with two brothers.
Kevin McGuire was stabbed to death after returning from a Kevin Bridges gig in October.
Kamran and Rizwan Ahmed pounced on the 51-year-old who was left lying in a pool of blood at the house in Wishaw, Lanarkshire.
A judge heard how Mr McGuire believed his partner Shona Briody had cheated on him with Rizwan.
The pair appeared at the High Court in Glasgow, with Kamran, 27, pleading guilty to murder.
His 31-year-old engineer brother, who also faced the same accusation, admitted to the reduced charge of assault.
The pair were remanded in custody pending sentencing next month.
Popular Mr McGuire was a well known door-to-door agent for a loan company.
The High Court in Glasgow was told Mr McGuire and Ms Briody had been in a relationship for 14 years.
But it emerged he had accused her of having slept with Rizwan, who lived with Mr McGuire’s niece.
Prosecutor Derick Nelson asked Ms Briody: “Kevin McGuire thought there was something between you and him?”
She replied: “Yes, he did. He would bring it up, he was not happy about it.”
The night before the killing, the couple went to the Kevin Bridges gig at Glasgow’s Hydro.
Mr McGuire ordered a whisky at the Hydro while Ms Briody had a fruit cider.
But, after taking their seats, Ms Briody recalled her partner “getting a bit more upset”.
She said: “This was when he started getting the stuff in his head about Rizwan.
“He was asking was I going to his house. At this, I felt that I wanted to leave.
“He just seemed that he wanted to have an argument about Rizwan again.”
Ms Briody decided “enough was enough” and left mid-gig. Her son picked her up and took the mum home.
As they were in the car, Mr McGuire later called to say he was heading to the Ahmed house in Wishaw.
Ms brody feared the worst believing her lover would be attacked.
The court heard Mr McGuire ended up in a row with the Ahmeds outside their home.
Mr McGuire then tried to flee, but was held by Rizwan before his brother smacked him with a baseball bat.
The victim was likely knocked out, but managed to stagger away. However, the Ahmeds soon jumped into a friend’s car and tailed him.
They found Mr McGuire outside his home pouncing on him in the garden. Rizwan repeatedly punched Kevin who was battered against his front door.
Mr Nelson then explained: “Kamran Ahmed was carrying a weapon with a long blade.
“Rizwan Ahmed stepped back… Kamran then repeatedly struck Kevin McGuire.”
Kamran was heard to tell a woman: “We need to go. I’ve just killed a guy.”
Ms Briody could see her lover being attacked through the frosted glass of her door.
She said: “Kevin was not moving. I felt scared and numb.”
Mr McGuire was discovered lying in a large pool of blood. He was taken to hospital but never recovered.
He had a number of stab wounds with the fatal one to his leg.
The brothers fled to Glasgow – it was there they were traced three days later.
The Ahmeds had originally had gone on trial before entering guilty pleas.
The duo also admitted to the earlier assault on Mr McGuire shortly before the killing.
Lord Tyre deferred for reports until August 1 in Edinburgh.