The body of Wendy Mann, 26, was found on her kitchen floor in West Bromwich in August 2015.
Leroy Sterling, 63, of Guns Lane, denies murder and the earlier attempted murder of her lover, Trevor Tyndale, Wolverhampton Crown Court heard.
Pathologists found multiple fractures in her neck, a pattern "commonly found in people strangled," the jury heard.
Mark Haywood QC, prosecuting, told the court Ms Mann's brother became worried when he could not contact her.
He went with his wife to his sister's first floor flat on Chapel Street where they found her body.
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The prosecution alleges Mr Sterling attempted to murder Mr Tyndale on 11 July 2015 after learning of his ex-partner's relationship.
The two men went drinking at Mr Sterling's flat where the prosecution claims the defendant attacked Mr Tyndale, 52, with a blow to the back of the head.
Mr Sterling continued the attack, "forcing a knife into his neck, trying to choke him", the jury heard.
The prosecution told the court Mr Tyndale managed to escape Mr Sterling's flat and later went to hospital where he had an emergency operation for his injuries.
Mr Tyndale did not inform police about who attacked him fearing his affair would become known to his own wife, Mr Haywood claimed.
The trial continues.
A mother-of-three was strangled by her ex-partner after she began a new relationship, a court has heard.