An Eastern Cape man was the target of "devastating" sexual taunts from his wife before he allegedly killed her, the Grahamstown high court heard yesterday.

An Eastern Cape man was the target of "devastating" sexual taunts from his wife before he allegedly killed her, the Grahamstown high court heard yesterday.

"Her refusal to withdraw the divorce proceedings against the accused, along with her taunts that she was having the best sex of her life with her lover, would have been devastating and psychologically, and emotionally overwhelming for him," clinical psychologist Ian Meyer testified.

"Retrospectively, the accused's mental state appears to have deteriorated precipitously from the time he received a summons for divorce."

Jan Wilhelm Marx, 41, of Steytlerville, is on trial for allegedly shooting dead his wife Marita, 38. He had pleaded guilty to the murder on the grounds that he had acted with diminished responsibility, but this was rejected by the state and Judge Clement Sangoni changed the plea to not guilty. The court heard that Marx attempted to commit suicide after the shooting.

Meyer said yesterday there was a pathological co-dependency between the accused and the deceased that was exacerbated by her alleged infidelity.

"The accused may not have been able to differentiate between right and wrong and act accordingly," Meyer told the court.

Defence witness Hendrick Alberts, 23, said he stayed with the couple for five months and had a sexual relationship with Marita.

"Something did happen between me and tannie Marita and I had sexual intercourse with her two or three times a week. I know it was wrong but I am not made of stone. She satisfied me and I satisfied her," Alberts said.

"She treated him (Marx) very badly and ... abused and humiliated him in front of others."

Marx, who is severely disabled and walked with extreme difficulty, wept as he listened to Alberts' testimony. The trial continues. - Sapa