A policewoman was shoved through a glass door by a chiropracter's angry mistress after all three of them had shared the same bed following a drinking session, Birmingham Crown Court was told.
The officer suffered injuries following an argument about the chiropracter's wife, it was alleged.
Hazel Tempest (27) of Windermere Drive, Streetly, Walsall, has denied assaulting Louise Flanagin on May 24 last year.
Timothy Sapwell, prosecuting, said Miss Flanagin knew Matthew Hunter, a father of two and a chiropracter from Sutton Coldfield, socially and that she had also been treated by him.
He said Dr Hunter was married but was apparently separated from his wife who, at the time of the incident, was away in America.
On May 23 Miss Flanagin was invited to Dr Hunter's home, which he also shared with a business partner, and where they had a number of drinks.
Mr Sapwell said that at around midnight Tempest arrived and, as a result of what she was told, Miss Flanagin believed she was Dr Hunter's cleaner, when in fact she was his mistress. He said Miss Flanagin intended to go home but was persuaded to stay.
"The three of them ended up in one bedroom and, in fact, one bed together," said Mr Sapwell.
He said Miss Flanagin believed this was a situation that had been "engineered" by Dr Hunter and perhaps by Tempest as well.
There came a point, he said, when Miss Flanagin went downstairs to the kitchen and the two others joined her.
Miss Flanagin told the court that Tempest started shouting at her and saying bad things about Dr Hunter's wife.
She said that Dr Hunter's wife Caroline, who was also a chiropracter, had treated her mother and that when she had "stuck up for her" Tempest had pushed her "quite hard" through a glass door.
Mr Sapwell said the officer suffered various cuts, the most serious being to her shoulder which required stitches.
The trial continues.