The 84-year-old told jurors at Southwark Crown Court that he was left feeling "sickened" by his behaviour, blaming himself for the alcohol problem the woman developed.But he insisted that their affair was "consensual" and she was a "willing participant" in the string of sexual encounters they had.Harris faces 12 counts of indecent assault on four alleged victims between 1968 and 1986, all of which he denies.Giving evidence at the start of his defence on Tuesday, the artist rebuffed all the allegations, including claims from his daughter's friend - which relate to seven counts - but admitted they had had several intimate encounters beginning when she was around 18.He also revealed that he had a second affair with a woman that he and wife Alwen had allowed to live rent-free in an annexe at their home.When questioned about the allegations relating to his daughter Bindi's friend - which the alleged victim claims date back to when they were on holiday in Hawaii when she was 13 - the TV personality said their relationship only began when she was an adult.The entertainer told the court: "It was all consensual and everything that had happened, she had been a willing participant."But the veteran entertainer told the packed courtroom: "I felt that I had betrayed everybody... Betrayed their trust."Pressed by his defence barrister Sonia Woodley QC on why he felt such remorse, Harris told jurors: "Because I'd had an affair with their daughter who was much younger than me. An extra-marital affair."He said he felt "sickened by myself for being a part of it at all", adding: "I knew it was wrong. Here I was, much older than her. A very young lady who was many years my junior."Later, after receiving several "unintelligible phone messages" from the woman, Harris visited her at her parents' house in Norfolk.He said: "She was blaming me for the state she was in, destroying her life, she said," he told the court.CHAR(13) + CHAR(10)"I felt I had let everybody down, I felt I had let Alwen down, and Bindi down and (the alleged victim's) parents down, so I said "please forgive me", and she said, "I forgive you"."The woman asked for £25,000 so she and her boyfriend could open an animal sanctuary, he said, and when he refused she became "irate", beating him with clenched fists, and told him: "You'd better keep your eye on the weekend papers".The court also heard that Harris embarked on a second affair with a woman he and his wife allowed to stay in a separate annexe they built for their daughter around 1995/96.He said they allowed the woman, who was "down on her luck", to stay in the house rent-free, but a relationship developed between him and her."It gradually became physical," he told the court, and said his wife was "devastated" when she found out.During his first day in the witness box, Harris also outlined his rise to stardom, describing how he had created his famous "wobbleboard", and even singing a segment of his hit song Jake The Peg.The trial continues.