A 19-year-old mother in northern England was convicted of stabbing her then-boyfriend several times during a sexual encounter last year.

Zoe Adams admitted to dressing as a clown and plunging a knife into 18-year-old Kieran Bewick’s chest to "enhance" their sex life. She was sentenced on May 2 to 11-and-a-half years in prison. The incident occurred at her home in Cumbria, England, in July, according to the Sun.

Bewick, who was 17 years old at the time, was stabbed five times in the chest, thigh and arm causing a lung to collapse. Adams’ phone, which was taken by authorities after the incident, contained images including a woman with the caption: "Murder is like a bag of chips: you can't stop after just one."

Carlisle Crown Court in the U.K. heard the details of the attack in a police interview shown to jurors, including how Adams got into bed wearing clown makeup after Bewick told her that he had a fear of clowns. 

"She had diamond eyes, and a Joker mouth, with red lipstick on the lips, and she had her hands behind her back. She had a weird smirk on her face," Bewick said. 

Adams, however, told prosecutors that she had blacked out at the time and didn't have any recollection of the attack or placing the knife in the kitchen sink afterward. 

Judge James Adkin called the woman’s actions "cruel and sadistic," adding that he believed the teen meant to cause bodily harm. He also stated that the woman was a dangerous "offender," who planned the attack when she brought the knife and duct tape to her bedroom that night.

"I am sure that by that time you had already become disinhibited by drink and drugs and the more sadistic side of your personality had come to dominate," Adkin said. "You had decided to cause serious harm to Mr. Bewick during sex."

In his victim statement to the court, Bewick said the incident caused him to have trouble sleeping and that he is battling pneumonia while treating his lung injury.

"Having had time to think about it, I am convinced that she planned it. It wasn't personal. She was going to do it to someone and it just happened to be me. Strangely, that makes it easier to deal with," he told the court.

crime scene A woman was sentenced to prison for stabbing her then-boyfriend during sex. Police tape is pictured hanging on Feb. 26, 2005 in Park City, Kansas. Photo: Larry W. Smith/Getty Images)