Kyle Morley, 30, had been out for drinks with friends including father David Bettison, 43, in Hugglescote, Leicestershire, before the violent encounter on February 24.
On his walk home at around 2am, Morley – who was high on cocaine – came across Mr Bettison and his ex-girlfriend, Katie Lamb, 23, involved in a consensual sexual act in a village park.
Morley flew into a jealous rage and punched his ex-girlfriend unconscious, before fatally attacking Bettison by kicking and stamping on his head.
After the attack, Morley ran away leaving his ‘genuine friend’ for dead and ex-partner seriously injured, but later returned and told police he intervened after suspecting Bettison was forcing himself on Miss Lamb.
He was jailed for life
Despite denying murder, Morley was jailed for life with a minimum term of 18 years and six months following a trial at Leicester Crown Court.
Following Morley’s sentencing, Mr Bettison’s daughter, Gracie Mae Brown, 15, said: ‘I know my dad was not perfect, but he didn’t deserve what happened to him and neither do his family.
‘He was taken from us so cruelly and way too soon and we now have a lifetime of living without him.’
Mr Bettison’s mother, Jackie Haines, said: ‘When Did died something inside me died with him. There is no pain like a mother losing a child.
‘Only people who have gone through this devastation can really understand how it feels.’
She continued: ‘I have restless nights imagining his last moments and what he went through.
‘I have nightmares and I wake and wish this whole thing was just one big nightmare, but it’s not, we are living the nightmare.’