Not long ago, I asked Dennis Sobin how he came to be the "Hugh Hefner of Washington," and why he continued to open sex shops in the Washington area and publish sexually oriented newspapers like "Met Personals" and "Free Spirit."

The heat was really on at the time. The D.C. police had just arrested him for reopening his Godfather Restaurant on Wisconsin Avenue, which had been closed after three employes were charged with giving "indecent" performances instead of serving food.

A group of Logan Circle residents were protesting the opening of his "Met Personals -- Models Wanted" studio on 14th Street NW, and law enforcement officials in Maryland and Virginia had obscenity and pornography cases pending against him.

His legal costs were skyrocketing, but Sobin was cool. He was laughing. He was wondering why everybody was so hung up about sex. Then he told me this story about himself:

He said he once was a very nice person studying for his doctorate degree at New York University, when one day he took a walk along 42nd Street, through the city's pornography district, on his way to the library.

In a fit of boredom, he decided to go inside one of the theaters.

"That's where I started going wrong," Sobin said. "I just couldn't resist the temptation, the glittering signs. I just had to go in and look at the books, then the movies."

What he witnessed on the screen one afternoon was so amazing that he ran home to tell his new bride.

(I can't tell you what he said he saw, but suffice it to say that he learned there was more than one way to skin a cat.)

He said his wife laughed at him for being ignorant, and so Sobin vowed to learn more.

The following year, in 1970, he went to work for Al Goldstein's "Screw" Magazine, and wrote "investigative stories" under the name Dennis Phillips. His area of expertise: police harassment of the sex business. His most memorable story: "A Guide to Smut."

This was a big change for Sobin, who had a master's degree in sociology and economics and who had been an assistant planner for Nassau County. He said his interest now focused on the legal issues of censorship and prior restraint and the morality of free sex.

"I was learning things about myself, and I was having a lot of fun," Sobin recalled.

In 1976, Sobin came to Washington to try his own hand at publishing. He started with two newsletters, one on how to get government grants and contracts and the other on how to get sex. The latter proved more popular so the guide to contracts was dropped and Met Personals was born.

He'd get in trouble with the law, but when one of his modeling studios was raided, he'd open up another swingers club in another part of town.

A few months ago, when he tried to open up the modeling studio on 14th Street, D.C. City Council member Frank Smith (D -- Ward 1) joined the protesting residents and declared, "There are laws on the books that prevent these sexually oriented shops from opening . . . when this institution opened, it was illegal."

To which Sobin replied to the crowd, "Anyone is invited in my house to have sex or anything else they want to do."

Last week, Sobin, 41, was sentenced to 30 days in D.C. Jail on a 1982 conviction of operating the Playground Swing Club in Southeast without a license.

The sentence was altered to allow Sobin to participate in a work release program and he has vowed to "get back into the swing of things" as soon as his time has been served.

The moral of this story: Anybody with children, please, do not let them walk along 14th Street or 42nd Street in New York, and if they must walk that way, please, do not let them go inside.