In an unexpected twist to the Bo Xilai court drama, the former Chongqing party secretary admitted he had been unfaithful to his wife, Gu Kailai , but "still had feelings for her". Gu, who is serving a suspended death sentence for murdering Briton Neil Heywood, has been a key witness for prosecutors in the bribery and embezzlement case in the past three days. Bo had been publicly accused of "having and maintaining improper sexual relationships", among other accusations, by the Commission for Discipline Inspection last September. But details of his extramarital affair had not been included in the three charges brought against him. Bo yesterday voluntarily told the court about his infidelity when he tried to discredit Gu's testimony that he knowingly let her accept five million yuan to improve the family's finances when she and their son, Bo Guagua , were living overseas. "Gu Kailai is a woman with high self-esteem," Bo said. "She would never complain about financial issues in front of me. She arranged the whole thing - to send Guagua to study at middle school in the UK - and took off after informing me. "She did this because I had an affair before and she was furious. She took Guagua away, to a large extent, to get back at me." Bo argued that Gu's testimony was untrue as the family had no financial difficulties. He said her law firm was the most profitable in the country and she had opened five offices in Beijing. Gu had lied about "having to shut down the law firm" as it was her suggestion in the first place, he said. He said he remembered vividly the moment she broke the news to him, and how he felt she was being considerate in avoiding talk of conflicts of interest. "It was something she did for me and was very proud of," Bo told the court. Despite having called Gu's testimony unreliable and argued she had turned against him in order to receive a more lenient sentence, Bo contradicted himself by saying he would not "make such assumptions" as they were a couple, and said he would leave it for the judge to decide. "I still have feelings for Gu Kailai. She's a relatively fragile woman," Bo said. "She would be sentenced to death if financial problems were included as well. She stands to get out of prison sooner by reporting an offence [to the prosecutors]. "Who else could she report on? All allegations against me come from Gu Kailai." Pressed by the head judge to clarify his stance that Gu's testimony was trustworthy, Bo said he left it for the court to decide. The tension between one of China's most prominent and glamorous couples had come to light during the trial over the last three days, with Bo calling his wife "insane", describing her testimony as "comical and ridiculous" and Bo's lawyers saying she was a person "who has a habit of lying often". Bo also revealed they had spent far more time apart than together, with Gu staying overseas with their son since 1999.