While in Portland, Oregon, for a journalism conference last week, I boarded a rumbly old school bus for a tour of the city’s all-nude strip clubs. The bus was crowded, as good journalists never miss the chance to peek into a furtive subculture or, it turns out, to look at boobies.

Visiting five burlesque clubs in one night was a whirlwind education, but even more fascinating than the stage acts was the clientele. While men in buttoned-down shirts and loafers fixated on the gyrating sirens before them, I watched the watchers. Because when you strip away the pretense of dating and the art of romance, you get a little titillating insight into the male mating psyche — the naked truth, if you will.

1) It’s different strokes for different blokes.

Most guys will tell you a strip club is like pizza. When it’s good, it’s really, really good. And when it’s bad… well, it’s still pretty good.

But different dancers appeal to different fellas. Some guys on our bus fell hard for a surgically enhanced coquette in a schoolgirl get-up. Others swooned over a 6-foot-tall beach bunny whose Barbie-like proportions compensated for her lethargic undulating. Still others were enchanted by a tattooed, mohawked minx named Malice.

Small breasts and large. Short hair and long. Leather and lace. After a few bump-and-grind numbers, my friend Michelle and I were bored.

“You seen one,” she deadpanned, “you seen ’em both.”

But the men disagreed, gleefully dedicating themselves to the time-consuming task of finding their stripping soul mate, and lavishing her with a tender “WOOOOO-HOOOOOOO!!!!!” once they did.

2) Men appreciate fastidious grooming.

It would be unfair to say all men like their strippers shaved bald where it counts. But of the dozen-plus dancers we saw that night, nary a one of them had the hair God gave a hamster. No tidy triangle. No artful landing strip. Just a whole lotta bare there.

Strippers build their acts — their appearance, moves, and music — around tips, and if they’re going for the 10-year-old girl look, it’s because that’s what brings in the greenbacks.

I’m willing to entertain the idea that men fling money at these waxed-to-the-navel girls because they feel sorry for them — you know, because they look cold. But until it’s confirmed, can we all at least agree that Puritanism has worked some funky voodoo on our nation’s sexual soul?

3) Men need, um, guidance.

Here is consolation for any woman who’s had trouble keeping a man’s focus on a dinner date: One stripper told me dancers routinely slap their thighs or click their high-heeled shoes together to draw customers’ attention back to the stage. And they’re naked.

4) Men are not fussy.

The women in our group were impressed by contortionists who could knot their legs behind their backs and by gymnasts who spun around their poles, upside-down, by their ankles. That’s talent.

But such artistry was wasted on the guys, whose singular criterion for a successful striptease was — and you gotta love their candor — an unobstructed view of the goods.

5) Men make lousy strippers — I don’t care how gay they are.

For variety’s sake, Michelle and I abandoned the tour and took a cab to a gay strip club, where beautiful men posed in cages wearing just Speedos and smiles.

We didn’t find them all that arousing, in part because they just sort of stood there flexing their grins, and in part because what turns on men is very different from what turns on women.

That said, if you know of a bus tour that showcases men who can make a woman laugh while hammering something and, say, packing their kids’ lunches, please sign me up.