The suit by the two – each is demanding at least $30 million – claims the photos, which were published last month, were used to "create a fictional and fabricated story" that was "hugely profitable" for the Enquirer, which is accused in the suit of publishing a "sensationalistic" story and manipulating and misrepresenting the photos.
Diaz and Nickerson claim they were simply sharing a brief goodbye that was an "insignificant and non-memorable occurrence involving co-workers and friends."
As the time the Enquirer ran its article and photos, Diaz's rep Brad Cafarelli told PEOPLE: "Shane Nickerson is a friend and associate of Cameron's, who works with her on her MTV show, Trippin'. They do not have any sort of romantic relationship whatsoever."
In his own online blog, Nickerson expressed shock (and a good sense of humor) over the rumors and accompanying photos, calling it a "ludicrous story."
"In fact," Nickerson wrote, "I told my wife, 'One of the reasons this is so stupid is because you know that if I was hooking up with CD you'd have been the first one I high-fived.'" Nickerson adds that his wife "laughed because she knows me."
Still, the suit reportedly claims that the article placed needless strains on Diaz's and Nickerson's personal relationships: hers with boyfriend Justin Timberlake, and Nickerson's with his wife and mother-in-law.
Diaz's law firm, Schillings, is also representing Timberlake in a suit against Britain's News of the World tabloid over a story claiming he cheated on Diaz.