Sally Bercow expressed her frustration after a photograph showing her apparently kissing another man was published by a tabloid newspaper.
She insisted the man was just a friend, that she had done "nothing to be ashamed of" and that the couple's marriage "works for us".
In the photograph, featured on the front page of the Sun, Mrs Bercow is wearing a brunette wig and has her arms wrapped around the man.
It was taken outside a central London nightclub on Saturday but the newspaper said there was no suggestion the pair left together.
Mrs Bercow is no stranger to publicity, appearing as a contestant on Celebrity Big Brother and a spin-off television show.
Her husband has indicated he does not wish to serve more than nine years as Speaker - a role to which he was first elected in 2009.
She denied their marriage was in any trouble.
"Of course I'm still together [with John], I don't need to apologise to John, I've done nothing wrong," she said.
"My marriage is my business. I couldn't give a damn what people think."
Mrs Bercow was made to pay £15,000 to Lord McAlpine last year over her infamous "innocent face" tweet.
She posted the defamatory tweet two days after a Newsnight report last November wrongly implicated the Tory peer in allegations of sex abuse.
Mrs Bercow settled the libel action brought by Lord McAlpine after the High Court found a tweet posted by her was highly defamatory.