Sheffield Crown Court was told how in an interview given to the police, Alison Moss described how what began as a friendly drinking session with her boyfriend David Webster, aged 50, and Craig Wild, 49, turned nasty after Webster flew into a jealous rage.
Moss said Webster, of Gibraltar Building, Shalesmoor, said a fight broke out between the two men at her home in Fox Walk, Walkley after Webster asked Mr Wild if he found Moss attractive.
She said: "Craig said 'she's not an ugly woman is she' and they started fighting. I calmed it down after about 20 minutes."
In the transcript of Moss' police interview read out in court this morning, the jury was told how after believing she had defused the argument Moss went to use the bathroom.
The 47-year-old says while she was using the bathroom she could hear Webster, the second defendant who has admitted one count of murder, speaking to Mr Wild at a normal volume.
But on returning to the living room Moss said she saw Mr Wild throwing bleach from a pink bottle over Webster, who was clutching a brown-handled kitchen knife.
She said: "He [David] punched him and punched him, there was blood everywhere. There were arms flying, there was blood flying.
"I didn't want to look to tell you the truth. I didn't want to see it.
"I was sat on the sofa with my hands over my eyes.
"There was someone knocking on the back door and someone on the front. I went to run and he [David] said 'don't open the door'. He said 'you're next'.
"Craig was on the floor. As I went to run I tripped over Craig. It was really slippy because there was so much blood everywhere.
"He told me not to open the door, but I did. There was just one police woman standing there.
"I said 'don't go in there, there's a dead body in there'.
"I didn't want her to see what I had."
The jury were shown items of blood-splattered clothing including a lilac, long-sleeved top and blue and white Adidas trainers the prosecution say Moss was wearing at the time of Mr Wild's murder.
They were also shown CCTV footage of Moss wearing the same items of clothing as she visited shops including Wilkinsons, Tesco and Home Bargains in Hillsborough with Webster hours before Mr Wild was murdered on August 25 last year.
But when questioned by police the following day, Moss denied owning either the lilac top or the Adidas trainers, which were both seized from her flat by police.
"I don't know how it [the top] got there. Maybe it was mine and I got blood on it when I was self-harming in it," said Moss.
She added: "I've only got one pair of trainers and they were the brown K-Swiss ones I was wearing when I got arrested.
"David had left a couple of pairs of trainers at mine."
During the same police interview Moss told officers she had known Mr Wild for around two years, and that she had met him when they were accessing the same services for alcohol dependency.
"He was a nice bloke. He goes to work and has a Jack Russell. I used to have a drink and a smoke with him," said Moss.
When asked about Webster, Moss said the pair had known each other since she was 13-years-old and they had met again shortly after he came out of prison earlier that year.
They had been in a relationship for around three months when Mr Wild was murdered.
"David can be the nicest man you'd ever meet. But when he drank vodka he became very violent. I kept begging him not to buy it, I don't know why he did," Moss told police.
In the hours leading up to Mr Wild's death, Moss said she and Webster had been drinking vodka, lager and cider and that she had smoked £40 worth of crack cocaine Webster had bought after getting paid earlier that day.
Moss denies one count of murder.
Webster is due to be sentenced at the conclusion of this trial.
The trial continues.