A "jealous" lover shouted "if I can't have you, no-one else will" as she threw acid over her ex, a court heard.
Berlinah Wallace, 48, is accused of dousing Mark van Dongen, 29, with sulphuric acid after the pair's five-year relationship broke down.
Bristol Crown Court heard he chose to end his life in a euthanasia clinic when the pain from his "horrific and catastrophic" injuries became unbearable.
Ms Wallace denies murder.
The court heard Dutch national Mr van Dongen was left paralysed from the neck down and lost his left leg, the sight in his left eye and most of the sight in his right eye, after the September 2015 attack in Bristol.
He was later told he would require a "lifetime of constant and dedicated care".
In January this year, he travelled to Belgium where he ended his life in a euthanasia clinic.
'Calculated attack'
At the time of the attack, prosecutor Adam Vaitilingam QC told jurors, Mr van Dongen had begun seeing another woman and moved into a hotel.
The victim visited the defendant at her flat in Ladysmith Road, Bristol, because he was concerned that she was "in a bad way and self-harming", the court was told.
He fell asleep, jurors heard, and Ms Wallace laughed as she threw a glass of sulphuric acid over him.
The court heard Mr van Dongen ran into the street "screaming for help", where neighbours tried to help him, and he was taken to a specialist burns unit at Southmead Hospital.
Mr Vaitilingam said: "The physical and mental suffering that he sustained from that calculated acid attack were what drove him to euthanasia.
"Put simply, he could not bear to live in that condition.
"If that is right, we say, then she is guilty of murder."
