Dennis Spelling, 47, told police how his wife came home from an evening with friends and showed him the diary. 'She gave me the diary and said I should read it . . . everything became clear. I just went for her, I put my hands round her throat,' he said.
Afterwards he put her body over his shoulder and dumped it in a woodland. It was found the next day, soon after Spelling had reported her missing, the Old Bailey was told.
Spelling, of Harlow, Essex, denied murdering Patricia, 49, last February but admitted manslaughter on the grounds of provocation.
Brian Higgs QC, for the prosecution, said it was Mrs Spelling's habit to 'maintain a diary in which she recorded details of her sexual relationship with Robert Parker in addition to her sexual experiences with another man, John Baker'.
One entry read 'great, showered together, went to lunch, played badminton just me and Bob, felt really special'.
Spelling, a laboratory technician, was suspicious about the relationship with Mr Parker after he saw them behaving with 'excessive familiarity'.
His suspicion 'arose slowly in his mind . . . it was something he was unprepared to believe and blamed himself for unworthy thoughts', James Wadsworth QC, for the defence said.
He was described as jealous of his wife but not unduly. All three of his daughters still wanted him back, the court was told.
Judge Neil Denison told him: 'You are a respectable, hard-working man with no tendency at all to violence and for nearly 25 years you were a good husband and your wife let you down. In a way you have punished yourself more than any punishment I can impose.'Reuse content