A schizophrenic teenager who stabbed a woman while they were acting out a sexual fantasy inspired by a scene from the TV programme Shameless, has been detained indefinitely in hospital.

Jordan Robertson, 18, who later said he had been hearing voices, asked the victim to get a knife, as they began having sex after they attended a party together, Bradford Crown Court heard yesterday.

Prosecutor Abigail Langford said the woman was not alarmed by the request, having previously discussed the fantasy with Robertson, and said to him “You’re going all Shameless on me.”

The court heard Robertson’s behaviour became increasingly strange as he ran the knife over himself, before stabbing her in the face “suddenly and without warning”.

She received 11 wounds including three to her hands as she defended herself, Miss Langford said.

Robertson, of Braithwaite Avenue, Keighley, said: “I need to die, I’m crazy,” before leaving the house and asking someone to ring the police, the court heard.

In a statement made when she was interviewed in July, the victim said she had suffered anxiety and nightmares since the incident and could no longer look in the mirror due to the facial injury.

Sentencing Robertson on a charge of wounding with intent, Judge Jonathan Durham Hall QC said he posed the “strongest, clearest” present danger to others and himself.

“The offence was committed with a knife which you asked her to find,” the judge said. “She thought it was some innocent game but it turned into a very real nightmare. It was during a sexual setting, you were responding to voices, you were exhibiting strange and terrifying behaviour then, before and after the attack.”

He told Robertson he will not be released into the community until a team of a judge and psychiatrists are satisfied the risk he poses is “manageable”.

The court heard Robertson had no previous convictions and was responding to treatment for his mental health problems.