Even if you haven't listened to "Loveline" since its heyday in the '90s, it's hard to imagine a world without it. A mainstay for more than 30 years on Los Angeles radio, the show — a call-in program where viewers asked their deepest, darkest questions about sex and relationships and everything in between — was eventually nationally syndicated.

Now "Loveline" has reached the end: Host Dr. Drew Pinsky confirmed Thursday night's episode will be the last. Adam Carolla, who co-hosted from 1995 through 2005, will also join him for the final broadcast. "The 'Loveline' brand is still strong and perhaps we will bring it back some day," Pinsky said in a statement. "But for now, this version is ending and I will be focusing on all of my other projects. It has been a privilege to have served the listeners and share deeply in personal stories."

So why is it ending? In a word, money. Pinsky, who joined the show as the expert in the "Ask the Surgeon" segment, said he has essentially been hosting the show for free in recent years. Probably not an issue, considering he has all that cash rolling in from one of his many ventures from VH1 ("Celebrity Rehab," "Sober House"), but still not ideal.

"The reality is there's not been a business model for the show for a couple of years," Pinsky told KROQ-FM, which has aired "Loveline" since the early 1980s.

This might be surprising to hear — when do people ever tire of weird, anonymous questions about sex? The answer is never, but the market for call-in radio shows has rapidly changed, especially since the rise of podcasts and other various Internet advice channels.

It's a sharp contrast from when the show originally took off. In 1996, The Post's Marc Fisher explored the rise of sex-talk radio, from shows like "Loveline" to "Sextalk and Slowjams." Here's a snapshot of the trend from two decades ago:

Love is in the Airwaves

By Marc Fisher
Nov. 5, 1996

The caller, Niecy, wants to know what to do about her sexual feelings for her uncle.

"I look at him and I start to get hot," she says. On the air. To thousands of listeners, many of them teens.

Justine Love, WPGC-FM's "lovely sexpert," as she is introduced Sundays through Thursdays at 10 p.m., says, "Well, you know you can't do that. You can look at him, just look at him, don't do nothing else. Okay? Bye."

Few radio formats are blossoming these days. Even conservative political talk, the hot ticket of recent years, is cooling off.

But one kind of program that is racking up late-night listeners here and around the country is a shockingly explicit form of talk radio devoted to sex and relationships.

"Sextalk and Slowjams" is two hours of brief conversations about two-timing lovers, inventive entwinings of human bodies and the clash between pleasure and disease — all blended with romantic ballads of the Phyllis Hyman/Teddy Pendergrass/New Edition ilk. Adimu Colon (radio name: Adimu), a 22-year-old deejay in his second radio job, pulls the package together with an earthquake of a baritone, the kind of voice that makes women rumble.

Adimu's sidekick is Justine Love, radio moniker for a 42-year-old sex educator who has worked with area schools and churches for two decades. With the lights dimmed and a single candle flickering between them, the deejay and the sexpert work in an eighth-story studio overlooking the Beltway in Greenbelt. Love can be cooingly seductive in on-air banter with Adimu. But she can also be tough.

A giggling young woman named Candice boasts that she's two-timing her boyfriend by taking up with a guy she's just met.

"What were you using?" Love asks.

"Nothing," Candice replies, chuckling nervously.

Love senses what the call is really about. "Oh, are you pregnant now?"

"Yes."

"Is it his baby?"

"No."

"Candice, you had unprotected sexual intercourse!" Love admonishes. "You're playing Russian roulette with your life, girl. Be careful."

Love aims to teach, warn and entertain, all at once. "When they're doing something bad, I'm not here to chastise them," she says. "It's to disturb their thinking and let them know their behavior puts them at risk."

But there are also plenty of calls that serve only to titillate. There is talk of inter-species relationships, of hermaphrodites, of preferred styles of oral sex.

"We're trying to be very responsible," says Jay Stevens, program director at WPGC (95.5 FM). "We don't want little kids calling up and talking about penises." A screener seeks to keep teens off the broadcast; a six-second delay allows objectionable language to be deleted.

The show has been on the air only six weeks; ratings won't be available until January. But the phone lines are always busy (mostly with women), and the word of mouth is remarkable, especially among high school and college-age kids.

"Sextalk" is a local knockoff of another show that has Washington teens glued to the radio. "Love Line," a two-hour syndicated broadcast out of Los Angeles, is heard here on WHFS-FM (99.1) Mondays through Thursdays at 10 p.m. and Sundays at midnight. A comedian, Adam Carolla, and an actual physician, Drew Pinsky, sit in the studio, trying to be unbelievably cool.

Virtually anything goes in their moral universe. They talk about their own experiences with drugs and sex. They get serious when confronted with potential suicides, domestic abuse or fools having unprotected sex.

But kids who want to know about which drugs they can mix, young people boasting about their experience with threesomes and more, men and women looking for approval for promiscuity — all get a condoning, even celebratory welcome. Carolla is not above the occasional rape joke. And "Dr. Drew" seems to get his kicks out of young people describing their artificial ecstasies. "Loveline" and its imitators are mostly about making money — even advertisers like Chevy Chase Bank sponsor the show on HFS — and the format pushes broadcasters into ever more lurid accounts.

One of the beauties of radio is that it creates private worlds. Kids can listen without parents knowing; radios fit neatly under the pillow.

Radio can be a good place for frank advice about sex. But there's a fine line between smashing myths and providing kids with gratuitous jollies. These shows haven't found it yet.