A man who said he was raped by former Commons deputy speaker Nigel Evans at the MP's home in Lancashire has told a jury he had not given a false account to "save his conscience".
Giving his third day of evidence, the complainant denied he and the MP had consensual sex and he had "regretted it ever since".
He told the jury what he did regret was "my cowardice" at allowing himself to get into the situation where he ended up in bed with Evans.
The incident is said to have taken place after the complainant attended a dinner party last year at Evans's home in his Ribble Valley constituency where he had agreed to stay overnight in a spare room.
Preston Crown Court has heard the man, in his early 20s, say he had not invited or wanted any sexual contact, but that he got under the covers with Evans after he was "escorted" to the 56-year-old's bedroom.
The MP's account of events was that the pair kissed downstairs and that the young man willingly went to bed with him and they had consensual sex. The complainant said: "I regret my cowardice. I did feel angry, I did not feel responsible for Nigel's behaviour."
The alleged victim is one of seven young men that Evans is alleged to have sexually assaulted on various dates between 2002 and last year by using his "powerful" political influence to take advantage of them.
Evans denies one rape, two indecent assaults and six sexual assaults.