Let's get this out of the way -- slapping a penis or a vagina is not about BDSM. It's ridiculous that in 2015 I even have to say that there's nothing wrong with that between informed and consenting adults. What's weird is that this happens in totally non-BDSM scenarios, in the throes of regular, everyday passion. You see, kids, when a man and woman really love money, sometimes they'll be engaging in perfectly boring, average naked-time shenanigans on film when suddenly a vagina gets slapped. The woman squeals, the shenanigans resume, and that's how misconceptions are made.

When the young, male masturbaters that make up porn's target audience grow up and find themselves between the legs of an actual woman who isn't getting paid to react to sex with the excitement of hitting the Powerball, they'll often be under the impression that this is a thing most women enjoy, and the unsuspecting victim is going to end up very confused, because why? Why would you think that feels good? It doesn't even feel bad, particularly, but it's like you've just interrupted whatever presumably enjoyable activity you were just engaging in to poke me in the eye. Just, why would you do that?

gpointstudio/iStock/Getty Images

I'm positive that if you polled a representative sample of women, "I just love having my vagina manually assaulted" is not something you're going to hear often, though there are undoubtedly women who are into this. That's not saying much. Stand up, spin three times, and point at the first object you see -- there's someone who likes rubbing their crotch on that. (Hopefully not that specific one; you'll have to work that out with your roommate.) Just because you knew one woman who totally loved this doesn't mean you should spring it on someone unawares.

This is particularly common among those relatively inexperienced in the ways of sex -- something worked one time, so by God, you're sticking to it; it's all you've got. And don't confuse the absence of objection with enjoyment: You'd be surprised by the number of women willing to shrug off a little labia-spankin' in the spirit of not wanting to hold an awkward "sex ed. dos and don'ts" conversation when she's trying to get laid.

Wavebreakmedia Ltd/Wavebreak Media/Getty Images

But you'd also be surprised by the number of women who are perfectly willing to call a time-out to discuss exactly what the hell was going through your mind just now, like she's a head coach and you're the athlete who made a really stupid play. So don't assume she's into it and then proceed to pummel her puss. Just wait for the invite, then pummel.

In general, we could all stand to be a little less weird about bodily fluids. Unless you're equipped with a full-on American Horror Story gimp suit, you are going to get some of the more solvent parts of your partner on you; accept and embrace it. It's a natural part of sex. Spitting, as porn loves to feature, is unnatural, for two reasons.

You, the male spitter, from the female perspective.

One, if you think you're doing it for practical purposes, you should know that saliva is actually a really poor lubricant. You know how when you have chapped lips, you have to fight the urge to lick them, because you know it will just end up making them even drier? Think about that, but with a vagina. You can pause here if you have any apologies to make.

Two, it's legitimately repelling. When you spit in clothed situations, it's to show your disrespect for someone, or because you just put something gross in your mouth. Think about the implications you're making about your partner there. Unless you're doing some kind of racially charged police brutality roleplay, it's kind of insulting.

Iampixels/iStock/Getty Images

It's also lazy. Look, anal sex, for example, is a delicate operation, and if that's the care you're going to take with it, suffice it to say I'm having second thoughts about this whole thing. The first dude who spits in my butthole is getting donkey-kicked right off the bed, and I know dudes for whom spitting on their penises is an instant boner-killer. At least be hot about it? If you replace the lazy hocking with some long, slow licking, congratulations, you've actually now performed a sexual act.

Or just be a goddamn adult and buy some lube. It's chapstick for buttholes.

You have now experienced sex with a man who's watched too much porn. It's a sad fact of life that there's very little overlap between the positions that look the best on camera and the ones that are the most conducive to an actual dicking. The legs-behind-the-ears one is used because everything is visible, but considering that the goal here is to rub things together, its real-world utility is minimal at best. My office is my couch, OK? I am not that flexible. At worst, you're asking for a fart on the balls. I'm sorry, but there are a lot of unsexy organs you're squishing there.

The other most frequent offender is the one where you're going in from behind and riding high, so to speak, which is again a visibility thing. It's so that the cameraman can get that awesome "between the legs" shot. What's happening on the receiving end is that you're being literally fucked sideways. There's a reason that's a curse -- it feels like one, in the "evil sorcerer" sense of the word.

Comstock/Stockbyte/Getty Images

Now, regarding both of these positions, a little angling is a good thing. The key words there are "a little." So please, over-porned guys, you have to remember that if you want to give a woman a vaginal orgasm you want to stimulate the G-spot, not pretend it's a pirate and stab it with a cutlass.

Everyone with access to the Internet can confirm that ass-to-mouthing does happen, and it's because interrupting the scene to go clean yourself would be kind of a drag (or, if the actress has a really good contract, they are cutting, but you would never know). It just also happens to be a standout among your Dirty Sanchezes and Rusty Trombones in that it's legitimately deadly. You ever hear of E. coli, son? Does the phrase "bloody diarrhea" mean anything to you? How about "brain tapeworm"? Are you absolutely sure you want to risk brain tapeworms because your boyfriend, for some ungodly reason, thinks it's hot when you gobble his bacteria-slathered knob?

altrendo images/Stockbyte/Getty Images

While we're on the subject of penises trying to pull off an Around The World, there's another hole that is, let's say, butthole adjacent, and if you're attacking from the rear, it's real easy to slip back and forth between the two and, by doing so, ruin her whole goddamn night. So it shouldn't be a surprise that if you stick a shitty dick in a vagina, the woman can get a nasty UTI. If the woman you're trying to double-dip with has ever experienced the pain of a UTI, you're legally not allowed to blame her for bowling you over on the way to the bathroom for an Everclear douche.

I'd like to think that most men are sympathetic enough not to want to give a woman a case of fire-piss, so I'm sorry, you're going to have to either take a suds break between holes or pick a flavor and stick with it. Being a mature, adult male sex-haver means learning that when you go for the ass, you put blinders on your dick and you commit to the ass.

God help us all, Manna has a Twitter.

For more from Manna, check out The 5 Least Effective Life Hacks People Apparently Use and 5 Awkward Things Nobody Tells You Everyday Technology Does.

Are you on reddit? Check it: We are too! Click on over to our best of Cracked subreddit.

Cracked is up for a Webby Award! Click here and give us a vote for "Best Humor Website."