An ex-Royal Marine who is accused of strangling his wife to death has told a court he did not intend to kill her.
Former UKIP councillor Stephen Searle denies murdering Anne Searle, 62, who was found dead at their home in Stowmarket on 30 December.
Mr Searle, 64, told the jury how, four months before she died, his wife had discovered he had been having an affair with their son's partner.
He told jurors she attacked him and died in the struggle that ensued.
Mr Searle told Ipswich Crown Court that she stuck a knife into the sofa earlier that evening and later attacked him with a knife as he was leaving the downstairs toilet.
He said they fell to the floor as he tried to disarm her.
"My right hand was on her neck and I was more concentrating on my left, it was very difficult to hold her down," Mr Searle said.
"It was one-handed, open-handed as far as I can remember. I wasn't concentrating on that part of her body. I was concentrating on the threat."
He continued: "Eventually she stopped struggling and I... said 'I'm going to have a fag' and went through to the conservatory."
Asked if he thought his wife would come into the conservatory, Mr Searle said: "I was expecting it to kick off again, yeah."
'Just sat there'
He said he "just sank" when he found her lifeless later that evening.
Asked if he considered calling an ambulance, he told the court: "No, and I don't know why.
"I didn't even think about calling anybody, I just sat there like a bloody idiot."
He said he later called police.
Mr Searle denied that they argued that night about his affair with his son Gary's partner Anastasia Pomiateeva, who is mother to at least one of his grandchildren.
He said his wife discovered his infidelity in August 2017. He ended the affair and they continued living together.
Asked if he intended to kill his wife, he replied: "No."
The trial continues.