As our James Covert points out, fashion can be fickle, and so can the PR departments of fashion firms.

Net-a-Porter founder Natalie Massenet announced last week she is leaving as the online luxury outlet readies a merger with its Italian rival Yoox.

But three weeks earlier, a Net-a-Porter spokeswoman had hounded The Post’s Media City column, demanding a “correction” of its Aug. 9 observation that Massenet “looks headed for the exit,” citing her hemming and hawing in an interview with New York magazine.

“Could we kindly ask that the edit be made immediately?” Net-a-Porter PR manager Christine Kapp wrote. As evidence, she cited a 4-month-old press release saying she would be executive chairman of Yoox after the merger.

When asked at the time for a fresh statement, Kapp fell silent. Same deal last week.