Zoe Adams, 19, dressed in clown makeup and put a pillow over Kieran Bewick’s head “to make it kinkier.”
She then told Bewick — who was 17 at the time — to “trust me” before stabbing him in the chest, arm and thigh with a 10-inch blade, jurors heard.
Adams admitted to unlawfully and maliciously wounding the now-18-year-old Bewick with an intent to cause grievous bodily harm.
Adams, who was fascinated by serial killers, had asked Bewick if he was prepared to be tied up after smoking cannabis and downing half a bottle of vodka.
Carlisle Crown Court in the UK heard his description of the attack in a police interview shown to jurors — including how Adams had appeared wearing the clown makeup as he lay in bed.
Detective Constable Calvin Greaves said: “Any assault with a knife has the potential for fatal consequences.
In this instance, the young victim of this callous and violent attack has been very fortunate to escape with his life.”
“Adams told officers she blacked out and had no memory of the attack. Her 17-year-old victim is not so fortunate. He will have to live with the physical and mental scars of Adams’ actions for the rest of his life.”