A woman in a "love triangle" that allegedly resulted in a man being stabbed to death has told a murder trial: "It is my fault. If I had never brought him to my house he would be still alive. I'm so sorry."
Claire McGrath also said the man who was killed "burst into" the room where she was arguing with the accused and said "she's mine now" before the fatal row broke out.
Ms McGrath has been giving evidence in the trial of 40-year-old Keith Connorton of Deerpark Avenue, Tallaght, who has pleaded not guilty to the murder of Graham McKeever (32) at the accused's home on February 18, 2017. He is on trial at the Central Criminal Court.
She told prosecution counsel Brendan Grehan SC that she was still in a relationship with Mr Connorton.
They moved into Deerpark Avenue in November 2014 having previously spent time together in homeless accommodation. They have one son.
By February 2017 they were having problems and often argued, particularly over Mr Connorton's drug use, she said.
They had a "rocky patch" for about a year and, while Mr Connorton still lived at the flat, they did not share a bed.
"We fought all the time but we both love each other and wanted to keep trying," Ms McGrath said.
She had known Mr McKeever since childhood and they met again when she started volunteering to work with the homeless, she said. "We made a connection," she said, and "one thing led to another."
They had been seeing each other romantically behind Mr Connorton's back for about six weeks before Mr McKeever's death.
On the afternoon of February 17 she had an argument with Mr Connorton. He was "intoxicated" on tablets, she said, and she told him to come back when he was sober.
She then invited Mr McKeever to spend the night with her "in a romantic way". She bought a bottle of West Coast Cooler, while he bought six cans of cider.
Ms McGrath became upset as she revealed that the accused had a key to the patio door.
"I don't know why I thought he wouldn't come back - he always does," she said, adding: "It was just a bad lapse of judgment."
Her son went to bed at about 9pm and she and Mr McKeever did the "usual romantic things".
They kissed on the couch and between 3.30am and 4.30am they went to bed.
They started to kiss and undress and were "planning to have sex" when Ms McGrath heard a noise from the kitchen.
She said: "That's Keith" and told Mr McKeever to "stay here".
She went to the kitchen wearing a dressing gown, underwear and a bra. In the kitchen Mr Connorton was cutting a piece of cannabis with a kitchen knife.
He seemed "tired and cold", his nose was red and he had a jacket and hat on.
"He wanted to get into bed," she said.
She asked him why he was there and told him to "get out", that they had broken up two days ago.
"I tried to cover my own ass," she said.
Mr Connorton realised what she was wearing and asked her: "Is there somebody there?"
He started to cry, she said, and they started to argue while he still had the knife in his hand.
He told her he loved her, had ordered rings and was planning to propose to her.
Mr Connorton was "angry" and "upset" as he asked: "How could you do this to me?"
He was "disgusted" with her, she said, and his body language scared her.
She moved backwards, she said, and fell across the arm of a couch.
Mr Connorton was standing in front of her with the knife in his hand.
"I don't even think he realised he had it. He was so focused on the fact that someone else was in his bed," Ms McGrath said.
When she fell across the couch she let out a noise, like "aah or ouch", and that was when Mr McKeever "burst in" and said: "She's mine now."
Mr McKeever "charged into him like a bull", the witness said.
She said Mr McKeever was a much bigger man and knocked Mr Connorton across the room and on to a child's chair.
"He beat the crap out of Keith," she said, adding that it was like Mr Connorton was letting Mr McKeever hit him in the face and, although he had the knife, he wasn't using it.
Ms McGrath said Mr Connorton was telling Mr McKeever to get out, Mr McKeever was saying "she's mine" and she was telling them both to stop.
At the time she did not think that Mr McKeever had a knife but she said a knife photographed by gardai on the floor of the apartment did not belong to her and must have been taken there by him. He must, she said, have taken it with him from the bedroom.
She took the kitchen knife off Mr Connorton after Mr McKeever had been stabbed.
Mr McKeever said: "He got me," and started hitting Mr Connorton again but as he was punching him he turned and fell to the floor.
When they realised Mr McKeever was dead the accused became angry with Ms McGrath and headbutted her, the witness said.
He then said to her: "How could you do this to me? It's your fault."
She began to cry as she added: "It is my fault. If I had never brought him to my house he would be still alive. I'm so sorry."
The headbutt left her dizzy, bleeding and with two black eyes.
Mr Connorton said goodbye to his son and left before gardai and paramedics arrived.
Ms McGrath spoke to gardai shortly afterwards but she said she may not have given "the full extent of what had gone on" in her statement.
She was on Valium at the time and in shock and the seriousness of the situation had not yet hit her.
The trial continues today.