The Virginia man on trial for murder charges in the killing of his wife and another man testified Thursday that he yelled “police” when he burst into a bedroom at his home and found his naked wife on the floor with a stranger.

Brendan Banfield, who is accused of conspiring with Brazilian au pair Juliana Peres Magalhaes to kill his wife, Christine Banfield, and the stranger, Joe Ryan, is a former IRS agent.

Banfield said he went up to the upstairs bedroom because he heard somebody having “sex” and found his wife with Ryan.

“Brendan, he has a knife,” his wife cried out, Banfield testified.

Banfield, under questioning by his lawyer John Carroll, said he told Ryan to drop the knife. Ryan refused, he said.

“He said that she was his and that ‘she gave herself to me,’” Ryan declared, according to Banfield. “And Christine kind of yelled, moaned.”

Both Banfield and Peres Magalhaes shot Ryan, police have said.

“I did not want to shoot him,” said Banfield, who testified he was armed with his service weapon. “Um, I wanted him to let her go.”

Banfield said he was tending to his wife when he heard a shot and turned to see Peres Magalhaes holding a gun she had retrieved from his safe in the master bedroom.

“I was stunned,” he said.

The dramatic testimony came a day after Banfield, who is also accused of trying to pin his wife’s murder on Ryan, insisted he did not conspire with Peres Magalhaes to commit a double murder.

“I think that it’s an absurd line of questioning for something that is not serious that a plan was made to get rid of my wife,” he said. “That is absolutely crazy.”

But Banfield, who is 40, also told the court he launched into an affair with the 25-year-old au pair in August 2022, a little less than a year after he and his wife hired Peres Magalhaes to watch their daughter, who is now 7.

“I was definitely in love with her” at one point, Banfield admitted on cross-examination by lead prosecutor Jenna Sands when he was confronted with messages they had exchanged on Discord. “We weren’t together when Christine died.”

Banfield is charged with four counts of aggravated murder and using a firearm in the commission of a felony in connection with the killings on Feb. 24, 2023. He has pleaded not guilty and could face life in prison if he is convicted.

Christine Banfield had been stabbed multiple times in the neck, police have said.

Last week, Peres Magalhaes testified that Banfield was trying to avoid a divorce as their affair developed. She said they used Christine Banfield’s laptop to set up a fake account on the BDSM website FetLife.com.

They used the account, Peres Magalhaes said, to lure Ryan to the Banfield home for what he believed to be a fake-rape fantasy with Christine Banfield.

The plan, according to Peres Magalhaes, was to tell police they shot Ryan after he stabbed Christine Banfield.

Banfield said he’d never heard of FetLife.com before the shooting but said his wife had expressed “interest in bondage-type situations.”

The IRS man has admitted that both he and his wife had engaged in outside affairs. He said the reason he strayed was because he wanted to “have sex more frequently than we did.”

Banfield said he knew nothing about Ryan “prior to this incident in the bedroom.”

Peres Magalhaes was arrested on suspicion of second-degree murder eight months after the February 2023 killing. In 2024, she pleaded guilty to the downgraded manslaughter charge.

Banfield was indicted in the killing of his wife and Ryan nearly a year after Peres Magalhaes was charged in connection with the double homicide.

On the morning of Feb. 24, 2023, Peres Magalhaes dialed 911 and said a friend had been hurt, a police official previously told reporters.

Brendan Banfield then took the phone and told a dispatcher that an “unknown male” had entered his home, the official said.

“There’s somebody here. I shot them,” Banfield told a dispatcher in a 911 call that was played at the trial. “He stabbed her. There’s several marks on her neck. What do I do?”

Christine Banfield was found fatally stabbed in an upstairs bedroom, the police department said in a news release at the time. Ryan, who had been fatally shot, was discovered nearby, the department said.