A wealthy businessman "totally lost it" during a drink and drug-fuelled "rough sex" session with his young lover, leaving her to die at the bottom of the stairs, a court has heard.
John Broadhurst, 40, is alleged to have murdered Natalie Connolly at their home in Kenrose Hill, Kinver, Stourbridge, West Midlands, in the early hours of December 18, 2016.
The prosecution have alleged Mr Broadhurst may have launched an attack to "teach her a lesson" after he may have discovered she was talking to two ex-boyfriends and had sent a topless image to another man.
Mother-of-one Ms Connolly, 26, was found in a pool of blood, naked except for a skirt rolled up to her waist, at the base of the staircase.
She had more than 40 injuries across her body, jurors were told.
Among her injuries was a blow-out fracture to her left eye, said by the prosecution to be consistent with "punch or toe-poke kicks", as well as facial bruising.
A post mortem found she had died from acute alcohol intoxication and blunt force injuries.
Opening the case on Thursday, David Mason QC, prosecuting, said: "She died on her own after she had been left there by the man who said, and still says, that he loved her.
"He left her at the bottom of the stairs in a dreadful physical state, heavily intoxicated and very badly injured."
The prosecution said "on the face of it" the couple seemed happy, with a friend of Broadhurst describing him as "happier" than ever.
Mr Mason also told the jury at Birmingham Crown Court: "Natalie was being well looked after by John Broadhurst who, as you will hear, is a very wealthy man."
They had been due to fly out to Dubai for a Christmas holiday, though Miss Connolly was due to go out a day earlier.
The couple had been hosted by friends at the Hawthorns football ground to watch West Bromwich Albion entertain Manchester United.
There they were overheard by two others at the gathering joking about the forthcoming holiday to the Middle East.
Mr Mason told jurors: "Mr Broadhurst said they would need to calm down with their sex life as they were worried when Natalie was in her bikini her bruises would be on show and that would not look good in a Muslim country."
However, it emerged Ms Connolly had been in recent contact with two ex-boyfriends and a stranger, who lived in Dubai, and to whom she had sent a topless picture of herself.
The jury heard she had arranged to meet that man - whom she met online in the August of that year - when in Dubai.
On December 17, she made a recording of an argument she had had with Mr Broadhurst, in which he told her "you've changed, you're not the same person".
After the football match, the couple continued drinking and eventually Miss Connolly and Mr Broadhurst, were both driven home by his chauffeur who described having "no concerns".
Mr Mason said once at their house the "party continued", and Mr Broadhurst would later tell the police they had about two grams of cocaine and drank more alcohol.
Analysis of Ms Connolly's blood found she had a level of alcohol in her system equal to nearly five times the drink drive limit, and there were also traces of cocaine, amphetamines and poppers.
Broadhurst claimed it was Ms Connolly who "wanted masochistic sex", and the court heard it was a "shared" interest between the couple.
The court heard claims Broadhurst later told police he left his partner for a moment during their sex game.
But when he returned, he found Miss Connolly "woozy", bleeding from a head wound, and clutching the banister at the foot of the stairs.
Broadhurst told police his girlfriend was "incapable" of getting upstairs and he was unable to carry her up, in part because he had a "metal leg".
He is also alleged to have told police: "I got a towel and some spray, some bleach sort of spray to get the blood off the banister and off the door and I wiped her face as I sprayed I wiped her face with it, because I didn't want her to you know to look a mess you know."
Mr Mason said: "So, bearing in mind the anxiety the two of them had about showing Natalie's bruises when they were in Dubai, what on earth possessed the two of them to engage in behaviour that damaged Natalie in the way that it did?
"Or, as we suggest, is it the case that Mr Broadhurst has totally lost it with Natalie that night, beaten her with fists and weapons, punched or kicked her to the face, severely damaged her private parts, and lied about it afterwards to cover his tracks?
"You don't spray her face with bleach to clean of any blood that might be on her, do you?
"Did he do these things because he found things out about Natalie and did what he did to teach her a lesson, using cleaning products to clean her up?
"There may have been some sort of consensual behaviour at the start of this night's activity, but we say that you can be sure that, whatever may have started willingly, there is no way that Natalie either consented to or was able to consent to what John Broadhurst did to her after that, leading to her untimely, unseemly and tragic death."
Mr Broadhurst, of Blakeshall, at Wolverley, near Kidderminster, Worcestershire, denies murder and an alternative charge of causing grievous bodily harm with intent.
The trial, expected to last up to five weeks, continues.