A man colluded with his mistress to deceive his wife by sending manufactured text messages to each other days before her death.
Alan Evans, 35, denies murdering 32-year-old Louise after she found out he was having an affair with teaching assistant Amanda Chadwick.
Her body was found at the bottom of stairs at their Worcestershire home, with a skipping rope nearby, and an uncoiled vacuum cleaner on the landing on July 10 last year.
Ms Chadwick, a friend of the couple with whom Evans was having a sexual relationship, read out some of the manufactured text messages to the jury at Worcester Crown Court.
In one, sent to Evans but for the benefit of his wife, she said: "We're good mates - she doesn't know me at all.
"I'm just sad of the friend I've lost in Louise."
Evans, of Kidderminster, replied to that message: "If she was really a friend of yours she wouldn't even think you'd have an affair with her husband."
Jonas Hankin QC, prosecuting, asked Ms Chadwick: "Who were those text messages for?"
"Louise", she replied.
Mr Hankin asked why the pair had sent those text messages, in late June 2012.
Ms Chadwick, who was also married at the time, replied: "To throw them off the scent."
The pair had been carrying on an affair for months by that time after first meeting on the school playground in autumn 2011, with Ms Chadwick telling the jury that at the time she loved Evans.
Jurors also heard that the couple were checking into budget hotels for illicit meetings where they would have sex.
But Mrs Evans discovered their affair when she found that more than 2,000 text messages had been sent between her husband and Ms Chadwick.
She confronted Ms Chadwick and told her she would tell her boss at the school where she worked.
Later that day, Ms Chadwick sent a text to Evans, and Mr Hankin asked her to read it aloud to the jury.
As she read the message she began to cry.
It read: "That fat bitch is going into school to complain about me to the headteacher and says she's going to do whatever it takes to lose my job and make my life hell."