Robin Thicke's lawyer has threatened to sue U.S. tabloid editors over reports suggesting the R&B star's marriage to actress Paula Patton collapsed after they became involved in a "three-way relationship" with a masseuse.

The Blurred Lines hitmaker was back in the headlines this week (begs28Apr14) after bosses at Star and Ok! magazines published articles in which they claim Patton agreed to spice up their sex life by introducing a masseuse named Jasmine into their bedroom to satisfy her husband.

The tabloid reports suggest that the experiment "took a disastrous turn" when Patton discovered that Thicke and Jasmine were "carrying on a separate affair behind her back", but now the singer's attorney has denied the allegations and fired off warnings to the editors to retract the statements or face court action.

The cease-and-desist letters, obtained by the New York Post, read, "On behalf of Mr. Thicke, as well as (the alleged masseuse), we categorically deny every assertion of fact posited in your email (asking for comment) and are certain there can be no reliable, trustworthy source of any such story, given its gross deviation from the truth. Any purported source of such a story is lying.

"Publication of this blatantly false story absent a failure to fully investigate the truth combined with reliance on what has to be a flimsy source, will support a finding that the story is published in wanton and reckless disregard of the truth, leading to a finding of malice and the imposition of actual and punitive damages."

Thicke and Patton announced their separation in February (14) after almost nine years of marriage.