A jealous woman stabbed her boyfriend to death in a champagne-fuelled rage then declared: "I have just killed the man I love", a court heard.
Jeweller Elizabeth Hart-Browne, 27, is on trial at the Old Bailey charged with the murder of Stephen Rayner, 25, at their flat in Acton, west London, on September 17 last year.
Prosecutor Rosina Cottage QC told how a row erupted after the mother-of-two arrived home from a family party where she had drunk champagne.
With young children sleeping just feet away, Hart-Browne allegedly picked up a large kitchen knife and stabbed Mr Rayner three times, inflicting a fatal wound to the neck.
The lawyer told how the couple had been in a "volatile" relationship for six years.
She said it was an "on-off" and involved both physical and verbal aggression on both sides.
She told jurors: "The rows appear to have been stimulated by allegations of infidelity against Stephen Rayner and jealousy and controlling behaviour by the defendant.
"In the days leading up to the events of September 17, the defendant and Stephen Rayner had been arguing about his behaviour and her jealousy."
Hart-Browne had gone to a family party and returned home by Tube to find her boyfriend already in bed wearing a pair of shorts.
A loud argument broke out and she was heard shouting and crying, jurors were told.
A neighbour allegedly heard a woman screaming: "He's dead, he's been stabbed."
She ran outside and found Hart-Browne leaning over her boyfriend laying in a pool of blood.
After an ambulance arrived, Hart-Browne was found in a distressed state, barefoot and wearing only one earring.
Asked what happened, she allegedly told a police officer she stabbed him, saying: "I didn't mean to do it, I'm so sorry."
After she was arrested and taken to Acton police station, the defendant was examined and found to have some minor scratches and red skin.
The court heard she was distressed on being told Mr Rayner was dead and told police: "I have just killed the man I love."
In interview, she told how she had drunk champagne and wine that night but denied being drunk.
On arriving home, she said she got into bed fully clothed but became upset at Mr Rayner again.
She got up to have a cigarette and Mr Rayner began hitting her and holding her by the throat, she said.
Hart-Browne said she waved a knife at him and pushed her partner as he held on to her neck and hair.
According to her account, she hit him with the knife unintentionally.
She saw the blood and Mr Rayner held his neck, allegedly telling her: "You're mad you are" and walked out.
As neighbours ran to his aid outside, Hart-Browne said she panicked and went back to clean the knife and clear up blood around the television.
Hart-Browne, who sat in the dock wearing blue jeans and a pale blue sweater with her long blonde hair in a ponytail, denies murder.
Ms Cottage said: "The defendant says that she picked up a knife from the living room table to defend herself while she was being violently attacked and that during the struggle they stumbled and Stephen Rayner was accidentally injured.
"The prosecution say that she is lying and that she deliberately armed herself with a knife from the kitchen and just as deliberately stabbed Stephen Rayner with it intending at least to cause him serious harm, if not to kill him."
Toxicology tests showed the defendant was twice the legal drink drive limit.
The prosecutor told jurors the alcohol "may well have influenced her temper and decision-making".
Ms Cottage told jurors there was no evidence to back up Hart-Browne's account of being violently attacked.
She said: "The prosecution say that Elizabeth Hart-Browne has made up a story to avoid taking responsibility for her actions and that on that night, she stabbed Stephen Rayner repeatedly intending to kill him or seriously harm him, and that is murder."
In an opening address for the defence, James Scobie QC told jurors the relationship between his client and Mr Rayner was both "golden" and "grim".
He said: "She was emotionally dependent on the man she loved and the man she killed."
He read out a WhatsApp message she had sent him which he said summed up their relationship.
In the message of January 10 last year, she pleaded with him to change back to the loving family man who would "do anything for us".
In the past he would "hurt if I hurt" and would "not abuse my self worth to make himself feel better, this man who made me happy", she wrote.
She wrote that "all I want from you is for you to love me" and not think that "hitting, abusing me is okay, like telling people I beg for you to sleep with me, calling me fat and ugly".
She went on: "Calling me a poison slut, thick, telling me I'm a shit mother, dragging my past in our relationship, using my abuse as a child to make me feel worthless, throwing stuff I have told you in secret about to humiliate me, asking other women out, telling me you don't love me, dumping me to break me and then laughing at me with your friends to make me look deranged.
"You have done all these things and more.
"All I have done is fall in love with you."
Mr Scobie told jurors: "This is a case of complexity.
"You are going to know a great deal more about Lizzie Hart-Browne and the deceased in this case.
"You are going to be hearing about the golden parts of their relationship...and you are going to be hearing the grim parts."
But he told jurors it would be made abundantly "loud and clear" in the trial why she stayed with him.