A man threatened to cut his stepson's testicles off with a knife while his wife shut herself in their bedroom with some pills, a court has heard.

When his stepson asked him what he was going to do as his wife appeared to be self-harming, he lost his temper and threatened the younger man with a kitchen knife.

Perran Stephens, a RAF chef in his twenties, told the police Ian Sawkins had threatened to cut off his testicles, which had scared him and he called the emergency services.

At Truro Magistrates’ Court Sawkins, 49, of Toltuff Road, Penzance, pleaded guilty to assaulting Mr Stephens at Penzance on January 9.

Alison May, for the CPS, said Mr Stephens was visiting the couple and had been out drinking with his stepfather. When they returned to the home Mr Stephens saw his mother in a room with a medical box and some pills, shutting herself in, and putting herself against the door so that it would not open.

Mr Stephens called out to his stepfather: “Are you going to let your wife do this? This is my f***ing mother.”

Sawkins took up a knife and pointed it at his stepson’s throat, telling him: “You come into my house and disrespect it. I am going to slice your f***ing testicles off.”

Sawkins told the police he had had an argument that night with his wife and he had gone to bed. He had not understood why his stepson had been shouting at him, and agreed he had threatened him with a knife. He had drunk about eight pints and some wine.

Richard Cogar, for Sawkins, said Mr Stephens and his stepfather had been drinking fairly heavily that night. The stepson had confronted him after hearing that his mother might be considering hurting herself.

Sawkins had lost his self control, but his threatening behaviour with the knife lasted only a few seconds. He had been upset by his stepson’s abusive language.

The magistrates imposed a 12 week curfew for five nights a week, and told Sawkins to pay £145 costs and charges.