But Colin Critchlow, 23, of Wednesfield, West Midlands, was jailed for five-and-a-half years for the manslaughter of 18-year-old soldier Andrew Green, of Willenhall, West Midlands.
The jury at Northampton Crown Court was told that Critchlow, who had denied murder, stabbed Mr Green in the back four times then kicked him in the head with steel-capped safety boots as he lay dying.
The jury found Critchlow guilty of manslaughter on the grounds that he was provoked into the attack by his live-in girlfriend Joanne Rudge, 19, also of Wednesfield.
They had been told that she flaunted her affections for Mr Green in front of him.
Critchlow was also sentenced to a year's jail, to be served consecutively, after admitting stealing nearly pounds 14,000 from the safe of an hotel in Wolverhampton where he previously worked as a porter.
He asked the court to pass on his regret and sorrow what he had done to the Green family.
Outside court after the hearing members of Mr Green's family were in tears, and described the verdict as a disgrace.
"He has got away with murder. It is a disgrace," said Mr Green's grandmother, Elizabeth Green.
Mr Green's parents and other members of his family were often in tears as they sat through the five-day trial.
The jury had been told how Critchlow became suspicious that Ms Rudge, with whom he has a one-year-old daughter, was seeing someone else.
He dialled 1471 after finding a number he did not recognise on their telephone - and got the number of Mr Green's parents home.
He then chased Mr Green in a car after spotting him kissing and holding hands with Ms Rudge in Wednesfield last August.
Mr Green stumbled and fell over as he tried to get away. Critchlow leapt out of the car and stabbed him four times in the back as he lay face down on the floor.
He then kicked Mr Green in the head, shouting: "Get up and fight you bastard."
Critchlow claimed in his evidence that he had not intended to kill Mr Green and said he had no memory of stabbing him with the knife.
Mr Green, a private in the Royal Artillery, had only returned home on leave the night before his death.Reuse content