The world’s largest producer of adult films is throwing an anniversary party tonight, celebrating a quarter-century of triple-extraordinary change.

Vivid Entertainment Group has grown from a two-room office to four-story corporate digs. Porn movies have bounced from seedy theaters to VCRs to PCs. And, in the most jarring change of all, the iconic cinematic sexpot Christy Canyon [pictured right] has embraced suburban motherhood.

The San Fernando Valley resident exposed to millions as Christy Canyon had lunch with a writer one day this week and spilled secrets of both her four-letter world and her domestic side.

The next morning, she was on the phone, worried that the newspaper story might spoil her well-crafted image by emphasizing the un-juicy details.

“It’s kind of a turnoff if people think about me cleaning the cat’s litter box,” she said with a throaty laugh.

Don’t be scandalized, fans – there’s still plenty of “Christy” in the woman whose family and friends know as Melissa. She hosts a dirty-talk show on satellite radio’s Playboy station. She runs an X-rated Web site. She self-published an autobiography (“Lights, Camera, Sex!”).

And she’ll dress up (or is it down?) to appear with other stars at Vivid Entertainment’s party tonight in Hollywood, where the Van Nuys-born, Universal City-based company will mark 25 years in business by opening a monthlong exhibit of erotic art from Vivid box covers and behind-the-scenes photography.

For Vivid Entertainment co-founder and owner Steve Hirsch, it’s a celebration of a venture that began with a film starring Ginger Lynn that was produced for a borrowed $20,000 in a rented house in Malibu in 1984, and now is credited with leading the skin-flick industry to higher production values and more enlightened business practices.

For Christy Canyon, 42, it’s a chance to reflect on her own porn beginnings in 1984 and her rise to iconic stature among Vivid’s “contract” actors until her final retirement from sex scenes in 1998.

Over salad in a booth at an Italian restaurant, she spoke in the nostalgic tone of all those Hall of Fame athletes who insist their era was the best and the kids today don’t know what they’re missing.

“The ’80s and ’90s were the best time to be a porn star,” said the dark-haired, tastefully made-up woman wearing jeans, an off-white sweater and a pendant necklace picked out by her daughter. “There was more of a heart in the ’80s and ’90s. There was more warmth and caring and loving. I really felt spoon-fed and coddled and taken care of. … I always felt the business was a safe haven for me.

“I didn’t quit because I didn’t like it. I quit because I was burned out. It was exhausting having sex every day.”

She complains that porn production seems too much like a business now, that she is put off by hearing girls talk about porn as a normal career choice, that she hates the rough sex acts demanded by companies that trade in shock value.

“I would not want to be a girl in the business now,” she said.

By her own description, Melissa (who asked that her last name not be printed out of concern for her children’s privacy) was a “perfect target for the porn industry” when the North Hollywood High grad was kicked out of the house after her parents divorced. She and the rest of the small circle of sex stars of the 1980s were classic “wayward girls looking for acceptance.”

She said Hirsch and Vivid, for whom she worked from 1990-98, became the “family” she needed. Told it sounded like a clich – girl seeks substitute for father’s love – she replied: “I’m lucky to have (a substitute). Some people don’t even have that.”

She worked on-camera on and off for 14 years, and toured as an exotic dancer. She made nearly 200 X-rated films, won porn’s equivalent of the best-actress Oscar, and was chosen for two industry halls of fame.

“She was one of the greats,” said Paul Fishbein, president of Adult Video News, the porn trade journal. “In that Ginger Lynn era, there were four or five huge names. Traci Lords was one of them, Christy Canyon was another one. She was natural, she was before the era of augmented breasts.”

But Fishbein said the attribute that’s still paying off is that “she had a good head on her shoulders and invested her money.”

Said Hirsch: “She is a great example of what you can be after a career in this business.”

Hirsch, who lives in the San Fernando Valley with his wife and two children, disagreed with his former star’s view that the porn industry was better in the old days.

“It is true the business is different from when Melissa was in it,” Hirsch said from behind his tidy desk in Vivid’s remarkably sterile office building overlooking the 101 Freeway. “The flip side is that there are vastly more opportunities for girls to make a living in the business now, to have control over who they work with and how they’re presented.

“I think the business is more professional than 25 years ago.”

It certainly is bigger, the approximately 200 Valley-based adult-content companies estimated to have produced $1 billion in revenue in pre-recession 2007.

Christy Canyon half-jokes that she liked it better when it was less “professional,” when it felt naughtier.

Now she lives what she calls “a double life,” split between reality and her porn character. “I have it all balanced.”

Fishbein, who remembers when Christy Canyon was a “quiet and shy” porn debutante, thinks “she’s in a really good place” today.

After her third divorce – and fueled by hard memories of her own family’s rejection – she decided she wanted to adopt children. She said she didn’t tell, and adoption officials didn’t ask, what she used to do for a living. She now has a daughter from China and a son from Vietnam.

Sometimes her two lives collide. Recently, she and her daughter were in a computer store. A salesman approached and said he’s a fan.

“What did that man mean, `I’m a fan’?” her young daughter asked.

Thinking fast, Mom answered, “He means he listens to my radio show.”

She figures that by the time her kids are old enough to understand her past, it’ll be too far in the past to be an issue.

Vivid’s photo exhibit, called “All American Porn: 25 Years of Erotic Photography From Vivid Entertainment,” will include photos of a wavy-haired Christy Canyon in what she remembers as her glory days.

“I did it, I had fun, I loved it,” she said. “Thank goodness I don’t need (financially) to do it anymore. Being a mom, I don’t want to do it anymore.”

But she said she’s happy keeping one stiletto heel in the ultimate show business, still playing Christy on the radio and at events like tonight’s.

“If I was Melissa all the time,” she said, “I’d get bored.”

“All American Porn: 25 Years of Erotic Photography From Vivid Entertainment” runs until March 13, Tuesday through Saturday, noon to 6 p.m., at World of Wonder Storefront Gallery, 6650 Hollywood Blvd. in Hollywood. Tonight’s party, open to members of the public 18 and older “on a space available basis,” starts at 7.