A prison officer took a woman who had been released from jail back to his matrimonial home and had sex with her, a jury heard.
Iain Cocks is also alleged to have fondled the same woman on a waterbed he shared with his wife.
Leeds Crown Court heard Cocks, 51, met the woman after she had been released from HMP New Hall, in Wakefield, where he worked as an officer.
The woman gave evidence at a trial today where Cocks is accused of two offences of misconduct in a public office and sexual assault in relation to two other inmates.
She described how she met Cocks during a night out in Barnsley in June 2016 after she had been released on licence.
Recalling the encounter, she said: "He has come up behind me, put his arms around my waist and picked me up."
The woman, aged in her thirties, said she had met Cocks about six times in the prison while she was serving her sentence.
She said Cocks, whose wife also worked at the same prison, bought her drinks and they kissed before she gave him her mobile phone number.
The jury heard she later met him in his car in an Asda car park before they drove to a country lane and held hands.
She said: "He described me as a one-off".
The witness said she went to Cocks's home in Barnsley on four occasions while his wife was working a nightshift at the jail.
She said they had sex in the spare room but she also slept beside Cocks in the waterbed he shared with his wife.
She said Cocks groped her while they were in the waterbed together.
The woman, now back in prison serving another sentence, described how there were wedding photographs of Cocks and his wife on the walls.
She said Cocks often told her how his wife would not have sex with him.
The trial continues