“My friends have a biased opinion of her, and her friends have a biased opinion of me,” Mr. Gower said. Broadcasting his gripes on Facebook is “a way to get your side of the story out there to everybody. That way, they don’t just hear her side.”

Ms. Andrews shares her fiancé’s view. “A lot of people aren’t with us if we have a fight at home," she said. This way, “All our friends can kind of comment on it.”

For the record, both Mr. Gower and Ms. Andrews say they are happy together and anticipate marital bliss. They find their Facebook parrying hilarious, and are not bothered by any loss of privacy.

Privacy on Facebook is a squishy thing to begin with, as most members know. Not only are there those advertisements from companies that — surprise! — know where you went to college, but there’s also the fact that Facebook accidentally sent private messages last month to the wrong people. In one case, a Wall Street Journal editor found his Facebook in-box flooded with other people’s pillow talk.

To some couples who fight on Facebook, the battle for public opinion seems to be a driving force. Ryan Stofer, a 19-year-old college student from Hutchinson, Kan., said his arguments with an ex-girlfriend were little more than attempts to protect his reputation.

Image SO I SAID... Leah Ackerman-Hurst with her husband, Caleb. Credit... Peter DaSilva for The New York Times

“She’d be talking to her friends on Facebook about how bad a boyfriend I was, and I would be like, ‘No, I was decent,’ ” he recalled. Eventually, Mr. Stofer’s friends became so fed up with the constant sniping that they started a Facebook group to protest it.