The John Travolta rumor mill keeps on churning … much to the chagrin of John Travolta. The actor’s former pilot, Doug Gotterba, recently dished to the National Enquirer on what he claims was a secret gay relationship with Travolta. Now, Gotterba is suing Travolta, claiming that the actor’s attorney, Marty Singer, sent him a threatening letter after the Enquirer story came out. The letter reportedly told Gotterba that he would be sued for violating a confidentiality agreement he signed when he stopped working for Travolta in 1987. Gotterba says he never signed it. Singer calls the lawsuit “ridiculous,” saying that Gotterba filed it to get his 15 minutes of fame. “We plan to get this meritless case promptly dismissed,” he added.