Television presenter Justin Lee Collins used details of his ex-girlfriend's sexual past as a "rock" with which to harm her, a court has heard.
Collins, 38, had a seven-month relationship with video games public relations worker Anna Larke, who is accusing him of harassment.
Prosecuting barrister Peter Shaw told the jury at St Albans Crown Court, in Hertfordshire, that she was an alcoholic, bankrupt and suffering from depression. "She's all of the above but she's not a fantasist," Mr Shaw said in his closing statement. "Does it make somebody with a drink problem - who has that relationship with alcohol - incapable about telling the truth on other matters? The prosecution say no, that would be manifestly ridiculous," Mr Shaw said.
He went on: "What would cause a woman with a drink problem, living in a nice flat in Richmond with the man she was besotted with, going on international holidays several times a year - holidays that she could ordinarily only dream about, to Miami and New York - having money paid into her account by this defendant, what could cause her to walk out on him? What could it possibly be? She wanted to be treated properly."
Collins met Ms Larke in 2006 at the Golden Joysticks Awards which he hosted in London. The following year they embarked on an affair behind his wife Karen's back, which lasted until 2008. The pair split up but resumed their relationship after the star's marriage broke down in late 2010. Collins and his wife had been married for nine years but together for 15 in total.
Ms Larke moved in with Collins in January last year after he left the marital home in Bristol, but problems quickly developed. The Crown alleges that the bearded, long-haired ex-comic was a controlling, sexually jealous boyfriend who made Ms Larke write down every sexual encounter she ever had.
Collins says the sex list, on which he features at number 37, was Ms Larke's idea to "unburden" herself. But Mr Shaw told the jury: "Why would a woman choose to do such a thing? You can see the level of detail in that book. Is it plausible that what he says, this was therapeutic, cathartic? It is not, the Crown say."
He added: "It was to haunt Anna Larke because despite this defendant's assurances about what a good thing it would be to do, he used it as a rock against which any self esteem she did have would be dashed."
Collins, who came to fame with Channel 4's The Friday Night Project, denies harassment.
In her closing statement, Collins's barrister Sonia Woodley QC asked the jury: "Has this previously pleasant man become a monster overnight and hit her constantly, hundreds of times causing hundreds of bruises? And yet we don't have any independent evidence that that was the case. Anna Larke describes the defendant as a wife-beater and that is a very serious allegation to make. But, members of the jury, there is something even worse. That is to be convicted as a wife-beater when you are no such thing."