A man has no memory of stabbing his girlfriend to death but accepts he killed her after finding himself covered in blood, a court has heard.
Jason Farrell is accused of murdering 22-year-old Sammy-Lee Lodwig at his home on Carlton Terrace in Swansea on 23 April.
The 49-year-old has admitted manslaughter but denies murder.
He told Swansea Crown Court they were both addicts and he had been "confused" after they took drugs together.
Cross-examining the defendant, prosecutor Michael Jones read out a statement from Mr Farrell's friend claiming he had called her the morning after Miss Lodwig's body had been found to tell her he had killed her.
"She asked you if anyone heard her scream and you replied 'no, I made sure', also telling her 'it was slow','' he said.
Mr Farrell denied the conversation took place and said it was possible his friend was lying.
The defendant, who had also dated the victim's mother, also denies causing grievous bodily harm with intent to Christopher Maher, days before the killing.
The jury has previously heard he suspected Mr Maher of being Sarah Lodwig's new lover.
At the opening of the trial, prosecutor Mike Jones QC read from what he described as a "chilling" letter written by Mr Farrell after his arrest.
It said he and Sammy-Lee Lodwig had argued upon returning to his flat on 23 April.
"Then the next thing I had her tied up and told her I'd had enough and I was going to kill her," Mr Farrell wrote, adding: "I did by repeatedly stabbing her in the face and throat."
Mr Jones also told the court Mr Farrell had knocked on a neighbour's window on the night of her death and said: "I killed her."
The neighbour told a friend, who accompanied Mr Farrell to his flat and saw the body of Ms Lodwig on a bed, the jury has heard.
The trial continues.