A LOVING father stabbed his son to death and tried to kill his baby daughter as revenge for his wife having an affair with his best man, a court was told.

Leslie Pepall, 28, killed four-year-old Ben with a knife and also stabbed Chloe - aged 11 months at the time - at their family home, a Winchester Crown Court jury was told yesterday.

The attack took place on August 6 last year after Pepall discovered his wife, Jean, 29, had left him for 32-year-old plumber Gavin Stevens, it was said.

Alastair Malcolm, prosecuting, claimed Pepall plotted the killings while he was staying in The Meadows, a psychiatric hospital near Southampton, to prevent his wife taking the children away from him.

A letter written to his wife and Mr Stevens from the hospital admitted as much, Mr Malcolm said.

Pepall's letter said he would not let Jean Pepall and Mr Stevens, who now live together, "play happy families together".

He said he felt deceived by the two people he trusted most in the world who had "done the dirty" on him.

And he apologised to his family and friends.

Mrs Pepall told the court her husband had been devoted to his children. The marriage had been under a strain and she had told him she wanted to leave him.

She admitted that she had begun an affair with Mr Stevens last year and it had continued when he had stayed in the Pepalls's home in The Shrubbery, Gosport, when his marriage ended.

On July 29, Mrs Pepall said she had left the family home with the children to stay with Mr Stevens in his caravan at Stokes Bay, Gosport.

Pepall admitted himself to The Meadows on August 4 but Mrs Pepall had only admitted she was having an affair on August 6, the day her husband was discharged.

She confirmed that she had agreed the children could spend the night with Pepall.

It was later that night that Pepall killed his son, attacked his daughter and tried to kill himself by stabbing himself in the neck, the prosecution alleges.

Pepall denies murder, on the grounds of diminished responsibility, but has admitted manslaughter. He has admitted the attempted murder of his daughter, now aged 19 months.

Proceeding