The story is that Monica Lewinsky masturbated with a cigar while President Clinton watched and masturbated as well. Yassir Arafat was supposedly kept waiting in the Rose Garden while this was going on in a room next to the Oval Office. The story has been widely talked about, moderately referred to in the mainstream press, and narrowly (i.e., in the Drudge Report, the New York Post, and various British papers) reported as fact.
Drudge (August 22) attributes the story to "multiple sources close to the case" and adds that "several major news organizations have confirmed the shocking episode." (No major U.S. news organization has printed it.) Drudge says it's unclear whether Lewinsky told this story to the grand jury--which is his way of saying he has no evidence she did.
Three days later the New York Post cited "one insider" who says Lewinsky had in fact told the grand jury about the cigar, and when Clinton was asked about it, he had to take an hour's break.
The foreign press have had fun with the story. A sample: "Still not inhaling, Bill?" (Toronto Sun); Clinton is the second President to have had "a Cuban Missile Crisis," (The Independent). A piece in the London Daily Telegraph ponders whether Clinton ever rolled around that particular cigar in his teeth in public.
The episode would qualify as "not having sex" under Clinton's controversial definition. And Clinton did refuse to answer some questions from Starr's interrogators about the details of his relationship with Lewinsky. But it is unclear whether the story is true--meaning only there is no good evidence that it is true.