Prosecutors claim that Robin Garbutt, 45, bludgeoned his wife Diana, 40, in their living quarters above The Village Shop and Post Office in Melsonby, near Richmond, last March and then blamed an armed robber.
Garbutt, who denies murder, was cross-examined at Teesside Crown Court by David Hatton QC, who put forward a series of propositions.
He said: “First, you had an unhappy, unfaithful wife who didn’t love you and found you inadequate. Do you agree?”
The defendant replied: “Totally untrue.”
Mr Hatton asked: “Secondly, if she left, you would lose your future and your shop.”
Garbutt replied: “I wouldn’t know what agreements we would make on that.”
Mr Hatton asked: “Was your wife aware of you using Post Office cash to fund this ailing business and lifestyle?”
Softly-spoken Garbutt replied that his wife would sometimes know how much was in the safe. He denies stealing cash from the Post Office. The couple were weeks away from going on holiday to the US, which would have triggered a Post Office audit.
Mr Hatton said: “You were about to be exposed and humiliated and you couldn’t face it.”
He suggested the couple discussed this the night before she was killed.
Garbutt was seen on the village green carrying a bag by a local woman at around 10pm - after he said he was in bed. He denies it was him.
Mr Hatton said: “You were leaving but you had nowhere to go. You had absolutely nothing in your own name and you went back.
“Later that morning you killed your wife in her sleep, didn’t you?”
The defendant replied: “That’s a terrible, awful thing to say.”
Mr Hatton alleged that Garbutt stole money from the Post Office to fund his wife’s lavish lifestyle and prop up the village shop business which was only making a £4,000 profit on a £200,000-plus turnover.
The couple enjoyed expensive weekends away in five-star hotels, luxury meals and Mrs Garbutt had a gym membership.
Mr Hatton said Garbutt had got away with taking money from the Post Office safe, and was “desperate” for cash.
He asked: “Was that desperation also driven, Mr Garbutt, by you trying to keep your wife happy, to keep the business afloat and provide her with a lifestyle that you could not otherwise afford?”
“I don’t think anybody would call me desperate,” he replied.
Garbutt said he had no knowledge of a note his wife drafted for her cousin’s husband, in which she wrote “I feel like I have been part of something seedy” and that they could perhaps get together later without the “emotional baggage”.
He did not know she had a page on the Badoo social networking site asking to meet “a guy 35-50”.
Garbutt worked from 4.30am in the shop while his wife, a trained postmistress, stayed in bed until late, the court has heard.
Mr Hatton said: “You once told her to get off her fat arse and help.”
Garbutt replied: “I said that once.”