Normal sex is about two people enjoying each other's bodies. Porn is all about looking right on camera, and that means some auteur is posing you to get the most artistic value out of your thrusting buttocks, even if you end up having doggy sex at an angle no human would ever choose to f**k in. For the woman, this often means that penis is pounding directly into parts of the vagina not meant to be pounded.

Ceridwen/Wiki Commons
You're smashing into spots that shouldn't be touched without stirrups, a speculum, and four years of medical school.

But hey, the suck hits both genders. Deep throating is not always awesome. If a girl's going down on you for a scene, she's going to be at it for a long time. We're still filming a movie, and it's a universal rule that nothing worthwhile gets filmed quickly. So she gets tired, and eventually you start feeling molars on the head of your dick. The viewer wants to see you jackhammering her throat with your dick, so you're basically ramming your c**k into teeth. Getting paid to receive oral sex is basically like getting your dick chewed on for an hour.

cokacoka/iStock/Getty Images
Even gum calls it quits after 20 minutes.

Also, lube gets on everything. I'm talking absolutely every part of your body and beyond. I shoot in my apartment a lot (phrasing), and now every doorknob has lube on it. On a hardwood floor, it's like black ice: My cats slip and go flying across the oiled-up wood on an hourly basis. (At least I sure hope that's lube.)

Another thing: The condom law that recently got passed is a hot topic, in exactly the sort of way condoms usually aren't. If you live in California and you voted on it, what you read on the ballet was "Do you think sex workers should have to wear condoms?" It's like "Should kids learn how to read?" Of course! But then there's the reality of it: Say a girl's doing a typical shoot with a guy. It'll wind up as 10 minutes of porn after editing, but it's gonna take four hours to film. And if you've ever had sex with a condom for four hours, congratulations on your nerve-deadened penis! Now apologize to your partner, because condoms are rough. Abrasive. They cause tiny microscopic tears in the vagina. You're running around after your marathon sex-epic high-fiving strangers on the street, but keep in mind that you basically just spent the runtime of Return of the King lightly sanding your partner's genitals.

IPGGutenbergUKLtd/iStock/Getty Images
"s**t, hold up. I forgot to do the epilogues too."

You might eyeball a guy's dong and think "He's not that big," and then he puts it in your ass and you realize just how large the head is. Here's a bit of folksy wisdom: You never know what something's going to feel like in your butt until it goes in your butt. There you go, kids: That's the new YOLO.

Jupiterimages/Stockbyte/Getty Images
Feel free to use that for your next inspirational tattoo.

Also, it's like Miss Manners always said: If you're shooting an anal scene, you've got to clean out your butt first. And buttholes can be, well ... buttholes. So after an hour of filming, you've digested your breakfast, and ... long story short, you've got to clean it out again. The best way to do that is with an enema. I was having a lot of anal one day thanks to two girls with strap-ons, and while I was in the bathroom cleaning out my butt, I saw James Franco next to me washing his hands. Apparently he was making some sort of art film in the same building. Someone walked by and said, "Hey, Mr. Franco!" I wanted to shake his hand, but ... butt.

I told the story to my friend, and he was like, "James Franco saw you naked?"

And I replied, "Well, I had a dog collar on."

If you're a man, at some point in your life you have found yourself lacking an erection when an erection would've really come in handy. Maybe you needed to measure something less than 4 inches and a ruler was not to be found, or maybe you needed to point to something when both of your hands were full.

AlexRaths/iStock/Getty Images
Or maybe you needed something to hold your doughnut while you stirred your coffee. Who knows?

Porn stars are not exempt from ninja erections. Erections are 90 percent mental, so usually you need to relax. And the first part of relaxing is accepting the situation. You don't stress out, like "Oh f**k, why am I not hard? Don't look at me! I can feel your judgmental eyes on my dick!" You just say, "Welp, this flag ain't flying," then you let everyone on the set know: "Hey, guys, it's gonna take me a minute to get this dick going, whoever wants to grab a soda or something, you probably got time."

Spencer Platt/Getty Images News/Getty Images
"We talking Big Gulp or Double Gulp time?"

A lot of times, easing the pressure fixes it. Sometimes it's a blood problem -- like if I'm in a situation where I'm upside down and a lot of blood flows to my head, or if I'm standing and it all flows to my feet. Most people I work with try Viagra, Cialis, or some sort of herbal over-the-counter thing they bought from the cleanest sex shop they could find, but those don't always do the trick if you're exhausted or starving or chained to a wall upside-down for too long.

Some guys use an injection called TriMix. I've never used it, but apparently you literally stab a needle into your penis and inject the TriMix, then it keeps you hard for hours. Even after you c*m, you just walk around with an obstinate boner all day. It's not common, exactly, but it's not unheard of.

pilipphoto/iStock/Getty Images
"Now I can order a baker's dozen; no worries!"

There's also a gel version of TriMix, and I'm going to quote the manufacturer for you on this one:

"TriMix-gel is an effective ED medication that is used as an alternative for patients who have failed on Viagra, Levitra, or Cialis and who cannot bring themselves to self-inject with a needle into their own penis."

Note how it just drops that some people can't "bring themselves to self-inject" into their own penis, as if you're some mincing pansy because you don't want to puncture your own genitalia.

Of course, some kinks are easier than others: Bondage can be really difficult. If you're tied up, you're losing blood flow. The instant someone cinches up those zip ties, of course you will immediately have an itch, so now you're trying to fight that and stay hard the whole time. Many times I've been tied up, suspended from the ceiling ... then the camera gets low on batteries, or a motorcycle goes by, and the scene takes an eternity to resume, and I've got to be hard the whole way through.

And there are the hidden pitfalls of exploring fetishes: For example, I had no idea I'd be turned on by clowns. But a couple of months ago, I was filming with this girl and got fucked in the ass by Harley Quinn (the Joker's girlfriend) while I was dressed as Robin. For the next clip, she was like, "I'm already Harley, so let's just put some clown makeup on you," and, well ... I guess I like clown porn now.

Minerva Studio/iStock/Getty Images
Some things you just can't take back.

You can find all the classy films Lance makes at Pervout.com, you can find more of his stuff on his blog and keep current with he and his cats via Twitter. He also works regularly with Kink.com.

Related Reading: Cracked recently talked with a man who went undercover fighting drug cartels. We also sat down with some drug dealers and a refugee from Scientology's secret space navy. Got a tip to share with us? Send it here.

Check out Robert Evans' A Brief History of Vice: How Bad Behavior Built Civilization, a celebration of the brave, drunken pioneers who built our civilization one seemingly bad decision at a time.

Through November 26, 2017, use Amazon promo code GIFTBOOK17 at checkout to get $5 of a printed book purchase of $20 or more! (excludes products sold by third-party sellers)