"I'm taping."

"Okay, good," he says.

Waters has evidently been through enough interviews -- taped and otherwise -- to know that nothing short of mechanical reproduction can keep pace with his manic musings as they spill forth from every direction and on a catalog of subjects: from porn ("I think it's the only reason possibly to have a television.") to his sexual orientation ("The press never asked me if I was gay for 30 years for the same reason my parents didn't. They feared the answer was worse than gay.")

The pauses between these bon mots aren't really there to allow more questions, but to let the one-liners fall with the necessary fabulousness. Because Waters is an aesthete -- make no mistake -- even if of a strange type, the type thoroughly dedicated to bad taste.

It's been 25 years since he ascended to his precarious and contradictory perch as film's leading auteur of trash. In retrospect, Waters' 1972 breakthrough, Pink Flamingos, defines his style -- not just because it initiated his popularity or because it ends with arguably the most shocking scene in cinema history (if you don't know by now ) -- but because of the badge of low-culture from which it took its name.

"I got the idea for the whole movie the first time I ever drove to California from Baltimore, which was actually to go to the Manson trial," he says. "I saw all these flamingos everywhere, in every trailer park, just in the middle of America, and I realized that it was really a symbol for something -- a certain kind of peaceful bad taste that I found kind of elegant in its own shabby way."

Today, Waters still uses that symbol to explain what can only be called his system of anti-aesthetics -- his full-blown theory of bad taste.

"Bad bad taste is a yuppie with a pink flamingo on the front lawn. [That] really offends me," he explains. "A real person that has a plaster one from their parents that they got from a trailer because they like it is beautiful, I think."

And in between the two -- between bad bad taste and real bad taste -- stands Waters, the well-bred Baltimorean enamored with the lower things in life. "I don't look down on my subject matter," he insists. "I look up to it. I wish I had the freedom of lower-middle class. I wish I had been raised that way. But I wasn't. I was taught to revere good taste, which I think is the only way you can appreciate bad taste."

Armed with that outlook and an array of obsessions (ever-changing, he says, but including violence, trials, and criminality in general), Waters has nicely settled into his role as the self-styled "Ambassador of Filth." He's made six features since Pink Flamingos, all of which dubiously immortalize his hometown of Baltimore, exposing its underside so Waters can explore the twisted America of fetishists, drag queens, and serial killers. "Come to town and be appalled," he suggests as a slogan for the Baltimore Chamber of Commerce.

While at 51 he is certainly to be counted among the elder statesmen of cult-cinema, he says that his vision hasn't changed all that much since the making of Pink Flamingos. One and all, he says, his films have had the same motive: upsetting liberal sensibilities.

"[Liberals] think everything is all right unless it's in their own life," says Waters, a self-described card-carrying ACLU member. "And as soon as it is, they panic. Pink Flamingos was a movie that was made to make fun of hippies. In Serial Mom, I asked liberals to root for a serial killer. Same thing."

Another constant has been the battles he's faced getting his films to the screen. Perhaps surprisingly, 1994's Serial Mom -- which starred Kathleen Turner as the spree-killing housewife of the title and which stands as his most accessible film to date -- was the one Waters had to fight hardest for. "They acted like they had just seen snuff," he recalls of the first time he showed it to industry execs.

And although his budgets have increased over the years -- Pink Flamingos was made for $10,000, Serial Mom cost $13 million -- he says that the process has remained more or less the same and brags that Serial Mom would have cost $20 million if it had been made by anyone in the Hollywood system.

His next project, Pecker, will be on a tighter budget of $6.5 million, half that of Serial Mom's. "It's about a kid that lives in Baltimore, a blue-collar kid that works in a sandwich shop and takes pictures of his loving but peculiar family on the side and exhibits them in the sub shop and is accidentally discovered by a New York art dealer and turned into a huge art star against his will," he says of the project, the details of which are still being negotiated. "It's about somebody who is really the most un-American thing you can be: somebody who doesn't want to be famous."

In addition to making movies, Waters has published three books, lectures frequently, and is one of the few guests who can be relied on to make David Letterman's skin crawl. In other words, far from it being merely a self-styled moniker, he really is the "Ambassador of Filth," and disarmingly so. His appearance is dapper, his manners refined, yet there's something not quite right, something vaguely -- which is to say, believably -- disturbing about him.

Maybe it's the mustache, that pencil-thin strip of smarm that mars an otherwise dandyish appearance, lending him the sleazy air of a carny con man. Once Letterman scoffed that it wasn't real and he responded by inviting the late-night host to touch it. He wouldn't, and it looked like the mere thought of it sent shivers up Dave's spine.

It would of course be silly to suggest that Waters' status and cultish mystique can be reduced to a tiny tuft of facial hair. But that doesn't mean it can't serve as a cosmetic reminder of his aesthetic maxim: "Any good taste needs a little bit of vulgarity to make it stylish."