Nick Gunn: He had affairs with women on his rounds . A councillor who stabbed his wife nine times with a kitchen knife after discovering her affair with the postman was yesterday found guilty of attempted murder. Joseph O'Riordan, 76, left his wife Mandy, 47, with life-threatening injuries to the chest, torso and back after flying into a rage over her infidelity. But today it can be revealed that her married postman lover, Nick Gunn, 41, had previous affairs with women on his rounds. While his wife last night refused to discuss her unfaithful husband, a former girlfriend revealed their relationship ended because he had been sleeping with a woman on his rounds. She also told how when she confronted him about the affair, he confessed that he had cheated on a previous partner with a woman he had been delivering post to. Mr Gunn started an affair with Mrs O'Riordan last year and the romance led to her husband placing a GPS tracker on her car as he hired a private detective to watch her movements. The couple had been married for ten years and had attended the Queen's garden party in 2013 for O'Riordan's work on the Diamond Jubilee celebrations. Yesterday he showed no emotion as a jury took just two hours and ten minutes to reach a unanimous verdict and find him guilty of trying to kill his wife. Brighton Crown Court had heard how he repeatedly stabbed his wife in their bedroom on October 22 last year, after arguing about the affair. The pair lived in a ground floor flat where Mrs O'Riordan worked as an estate manager on a residential home in Polegate, East Sussex. Mrs O'Riordan and Mr Gunn – nicknamed 'Tommy' by friends and family – had known each other for a number of years when he lived in the Sussex village and worked as a postman. Guilty: Joseph O'Riordan, 74, stabbed his wife Amanda, 47, (pictured together above) nine times with a kitchen knife at the home they shared in Polegate, East Sussex, after discovering her affair with postman Nick Gunn . Last year – despite having married three years ago and having moved with his wife Sara Saunders to Portslade, near Brighton – Mr Gunn and Mrs O'Riordan became lovers. But she was not his first, it is claimed. A 39-year-old former partner, who did not want to be named, said: 'We split up because he was having an affair. I saw that he had made a comment on Facebook about a 'lover' and I knew he wasn't talking about me so I confronted him. 'He admitted he had been sleeping with a woman he had been delivering post to. He told me that something similar had happened with a previous girlfriend as well. We were together for six years, and this might have happened more than once. I didn't find out until July 2011.' After that affair Mr Gunn married schoolteacher Miss Saunders, who said last night: 'I'm still married to him at the moment and I'm not interested in talking about him.' O'Riordan (left) was convicted of attempted murder today after a jury took just two hours and ten minutes to unanimously find him guilty of trying to kill his wife with a nine-inch kitchen knife (right) in October last year . O'Riordan was sitting on Polegate Town Council when he grew suspicious that his wife, Amanda, 47, was having an affair and hired a private investigator to follow her which confirmed her relationship with Mr Gunn . Mr Gunn has a Facebook page and describes himself on Twitter as: 'A Gamer, a Lover, a Postman and a friend of Death.' As the affair developed last year, O'Riordan first hired a detective to watch his wife and then set up a GPS tracker on her car. The £300 tracker reported back via text to O'Riordan's phone whenever his wife left home and gave the exact location of her vehicle. On one day alone on October 9 the tracker sent a total of 35 notifications to O'Riordan as his wife visited Mr Gunn at his then home in Portslade. O'Riordan used to run nightclubs in the South East before he retired and was also a councillor in East Sussex and became president of his local Royal British Legion. Mrs O'Riordan was a 23-year-old divorcee when she met the older O'Riordan in 1991. They married in 2004 and were seen by many friends as the 'perfect, loving couple'. Friends and family of Mrs O'Riordan arrived at Brighton Magistrates' Court (left) for the verdict today while O'Riordan's son Liam - from a previous marriage - also attended the hearing to see his father convicted . But as O'Riordan became older his wife essentially became his 'carer' and the court heard how she wanted more 'freedom'. Prosecutor Dale Sullivan said O'Riordan had 'clearly lied' when he told police officers repeatedly that he had stabbed his wife because he had 'just found out she was having an affair'. In reality he had known for weeks that she was seeing Mr Gunn. When Mrs O'Riordan gave evidence last week she did so from behind a screen so she did not have to see O'Riordan. She told the court: 'I loved Joe. I didn't want to hurt him. I never wanted to hurt him – even now.' O'Riordan is due to be sentenced today. Mr Gunn was unavailable for comment. O'Riordan will be sentenced for attempted murder at Brighton Crown Court (pictured above) tomorrow .
Councillor Joseph O'Riordan found guilty of attempting to murder his wife . Court heard attack occurred after he discovered her affair with the postman . Amanda O'Riordan, 47, in extra-marital relationship with married Nick Gunn . Postman Mr Gunn, 41, had previous affairs with women on his rounds .