A retired postmaster living in Helston was murdered by his lover over a spat about the purchase of a bottle of sherry.
Alexander Channer lost control and suffocated pensioner Colin Payne in his bed after tying him up and gagging him.
Chillingly Channer had acted out a similar fantasy 12 years before, when he bound and gagged another man during an act of false imprisonment.
But on that occasion, he was only given a caution despite the seriousness of the offence and was treated in a Bodmin psychiatric hospital.
Plymouth Crown Court heard 20-stone Channer cracked 72-year-old Mr Payne around the head twice with a rolling pin.
He then smothered him with two pillows after he bound his legs and hands and put a gag in his mouth.
Channer, now 54, admitted murdering grandfather Mr Payne at his flat in Sanctuary Lane, Helston, one day last June. He had previously admitted manslaughter which had been rejected by the Crown.
He was jailed for life and will serve at least 15 years before he is eligible for release at the age of 70.
Judge Graham Cottle said the victim was a man who “enjoyed a quiet and completely independent life” near his family.
He said Channer was in a relationship with Mr Payne, which was unknown to the victim's own grown up family.
The judge said in 2000 Channer “acted out a fantasy” with another lover when he applied restraints to him and kept him detained for several hours.
“The matter was eventually resolved by you being cautioned,” he told the bearded, bald and bespectacled defendant.
The judge said Channer again acted out the fantasy when he killed Mr Payne, who was found by his son on Father’s Day with restraints on various parts of his body and with a gag in his mouth.
Judge Cottle said: “It was a wicked act. Colin Payne was a much loved and missed man who met his death in quite appalling circumstances.”
He said the murder was triggered by a comparatively minor event – being asked to buy some sherry by Mr Payne.
Prosecutor Simon Laws QC told the court that Mr Payne lived a quiet life and liked a drink, with his preference being sherry from Tesco.
Channer had become a lodger at the flat and told police they were in a sexual relationship.
Mr Laws said Channer was reclusive and “rarely went out.”
He told police he was uncomfortable about going out in public due to his obese weight and if he needed to go to a supermarket would go late at night or in the early hours to avoid contact with people.
Channer is thought to have murdered Mr Payne on June 4. He then took the dead man's credit cards and travelled around the country using them before he was arrested in a Nottingham hotel two days after Mr Payne was found dead.
Mr Payne's body was not found for two weeks until his son Nicholas went round to visit his dad on Father's Day on June 17.
He could not raise him and had to use a ladder to break into the flat where he found his father's body in his bed and a rolling pin on the floor.
Channer told police he had harboured thoughts of causing harm to Mr Payne and killing him by smothering him.
Mr Laws said: “He described difficulties he had experienced going out in public and in meeting people and being abused over his size.”
He said on the day of the murder Mr Payne asked him to go and buy some sherry but Channer was reluctant to do so and this minor incident triggered the murder.
Mr Laws said for some bizarre reason Channer lost control and armed himself with the rolling pin before using pillows to smother him as Mr Payne cried out: “What are you doing to me? Why are you doing this? I love you.”
Channer, from St Austell, said it took “several minutes” to smother his lover as the victim kicked out with his feet and shouted for help.
Mr Payne's family said he was “a kind hearted man who would not hurt a fly.”
Paul Mann, QC, defending, said: “He never hid that he killed Mr Payne unlawfully. He wants help.”
Following the sentence Nick Payne, the victim’s son, said: “Our family would like to thank all the police officers and their liaison officers involved in this case for their professional and sensitive way that they have handed my father’s murder from the start to finish.
“Also a big thank you to David Osborne from Victim Support for his help and advice.
“We are pleased with the verdict but for my sister, rest of our family and myself we have been cruelly and prematurely robbed of a loving father and a central part of our family.
“We will never forget my dad and will now try and remember the happy times we have spent together instead of focusing on the needless and senseless murder of a good kind man.”
Detective Inspector Ellis from the Major Crime investigation Team, described it as an “extremely difficult and tragic set of circumstances” for Mr Payne’s family to cope with.”
He added: “I hope that this conviction today will help them to begin to move forward.”