Walking into “Grunt,” “Rimjob” or “Cell Block,” you can smell the perversity. It’s like napalm in the morning. It smells like victory. Like freedom. Like the mix of musk and terrified sweat from those men who in the 1950s were booked and jailed, shamed in mug shots whenever gay bars were raided.

President Obama, when he paid homage in his second inaugural address to the sites of various civil rights struggles (Selma, Seneca Falls), mentioned a gay bar (Stonewall). The gay bar has achieved such proverbial, iconic status I’m surprised it doesn’t have its own emoji.

Today shameless Sunday beer busts are as free and perverted as they are because the cover charge for our sexual freedom has been paid.

When the perverted are free, so is everyone else.

That’s why, when I enter a gay bar, I don’t just enter a place of booze and music. It’s a place where liberty reeks and sexual orthodoxy mutates.

Straight bars and gay bars are incomparable because they have incomparable histories. Like two different branches on an evolutionary tree, they’ve diverged from each other a long time ago and occupy two totally different habitats. It’s like comparing hippos and dolphins.

Places named “Bulge” and “Big Chicks” and “The Eagle” have naturally selected to move toward a more perfect perversity and freedom, testing the outer edges of sexuality and gender. Straight bars are, um, straight bars. It’s just not that heavy for them. Which is like totally cool.

The first thing to know is that a gay bar is a place where “The anus is as beautiful as the ear.” Self-help author Louise L. Hay actually wrote about such self-loving, body-part egalitarianism in her book You Can Heal Your Life. And while beautiful words are written about unmentionable body parts, adult film actor James Deen is publicly opening up such “gay” practices as rimming.

This is gay bar life peaking its head out of gay bars and into presidential speeches and straight adult films. They are places that foster the democratic eroticism of the toes, the pits, the hair, the nose, the earlobes, the what-have-you.

Gays know our bodies are gorgeous and silly at the same time. Look at the penis. It’s ridiculous and beautiful and it comes (pun intended because gay bars are also full of puns) in so many colors and shapes and textures that a gay bar’s only rival in displaying such diversity would be the skylines of major cities or the annual Penis Festival in Kawasaki, Japan.

This openness to body parts extends to a welcoming of society’s “weirdoes,” creating environments that feel like a cross between the Island of Misfit Toys and Edward Hopper’s Nighthawks.

Gay bars contend with a sexual and gender spectrum that has all genders and sexualities available like a smorgasbord. This has included, in my experience, tranny chasers, a gay cholo taking up too much space in his dancing wheelchair, towering drag queens, leather daddies, men dressed as puppies, girthy bull dykes and little people in sparkly suits and bowler hats. Bearded ladies have always needed a place to go where everyone knows their name and where scenes like the following occur:

A trans woman wears a bikini with heels, clapping to a cumbia in the center of the dance floor like she’s a happy abomination. No one in the crowd of wallflowers is offended by her. Or threatened by her. She doesn’t need to be punished or thrown out or regulated in any way. And if anyone yells out in Spanish, “Pinche puta sin papeles!” It’s probably her friend.

The two dancing queens who brought a loop of red fabric to the club, first wind and then unfurl themselves in mad twirls synced to the house music. Their choreography is so crazy gay their flaming might inflame those who hate to see men transgress the code of manliness. But their amateur Cirque de Soleil act is safe at a gay bar.

I was there. Saw it all.

In Berlin all the bars seem to have their own dungeons the same way McDonald’s has Playlands. The moans and groans in the subterranean, humid darkness merge into a soundtrack that is like something between a haunted house and a crowd enjoying delicious meal.

At the better gay bars you’ll see the deaf clustered in a circle of fast talking hands, old Mr. Burns nursing a drink in a corner, daddies with sons, creepers creeping, women with crew cuts and 70-year-olds remembering the 70s.

One septuagenarian sat next to me at a bar in Chicago where gays gather to sing along to musical theater like some stereotype gone wild. In our conversation he came out as a 1%-er. He’s among the 1% of the population with HIV that is actually immune to the virus.

He survived sex in the 1970s because he had the mutation CCR5-Delta 32 (found mostly in those of northern European descent). He smiled when he reminisced about all the sex that was going on in the 1970s and how glorious it was until, of course, his friends and lovers started dying.

A mutation in his genes had saved him and allowed him to live today. He was grateful. I was grateful for the message, given to me over a beer and barstools, that sometimes it’s the mutations, those queer instances of change, that make us stronger.

In the 1970s I was a baby stuffing my toes happily in my mouth while men were doing the same thing for each other at “The Male Box” or “The Sewers of Paris” in LA. Those bar patrons who survived probably remember the smell. Those who died probably didn’t imagine a day when marriage, rimming, sex-positive beer busts and the pursuit of happiness would be so much more open to all.