It's been said that the feeling heroin produces is the only thing better than sex - this is why we will never, ever try heroin. Sex is the funnest activity of all time, and unlike heroin, it it highly unlikely to make you join the dreaded "27 Club." There are times, however, when it's just not appropriate to be having sex (a lesson we learned the hard way, and have subsequently been placed on the lifetime ban list at 'Ice Capades.') During these times, we take solace in the power of the unconscious: Let's hear it for sex flashbacks.

One of nature's great mysteries, it's scientifically probable that a sex flashback is your brain's way of reminding you that sex is awesome and feels good, so you go out and have more of it, to produce offspring. Let's pretend that's not true, though, because that's horrifying. We prefer the theory that a sex flashback is a mystical gift from the heavens, which allows for a momentary relapse of pleasure triggered by memories of last night. Or last month, if it's been a dry spell. If it's been more than a month, you should get off the internet for a bit, maybe.

Sex flashbacks are not just memories, they're sensory-overload sexual time-machine moments, and many times they're involuntary-- A flashback can send an electric shock through your spine, and many times they are visible to those around you (visual cues to watch for: lip biting, flushed face, knuckle cracking, smirking.) Little known fact (since we made it up) Sex flashbacks are the leading known cause of sexting, which leads to repeat business. Which triggers more flashbacks. Best cycle ever.

Here's our list of the Top 5 places to have one, if you've got a good poker face.

During a Meeting

Top 5 Places to Have a Sex Flashback
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Your boss is droning about disappointing quarterly sales reports, and your coffee cup is drained. You're contemplating whether it's possible to commit Hari Kari with a highlighter when you remember Saturday night. Damn, that girl had some good balance in heels.

In line at the DMV

Top 5 Places to Have a Sex Flashback
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You got there when it opened, and it looks like you'll be there when it closes. You've been told you have none of the right forms, that your license renewal requires a PH test of your urine, and the person in the plastic bucket seat next to you is clutching a gerbil and mumbling the lyrics to the 'Three's Company' theme song. Just when you think the storm clouds will never lift, you're grinning about bathroom sex.

While fighting

Top 5 Places to Have a Sex Flashback
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She's an evil genius, and she erased all of the Real Steel off of the DVR on purpose, you know it. She ate the last Poptart, and has never bought a roll of toilet paper in her entire life. You can't remember what it is you even like about each other for a second, until she's leaning over the table yelling something and you remember the last time she was standing like that. Insider girl tip -- Definitely have sex right now, but be artful in your transition.

On a long, boring drive

Top 5 Places to Have a Sex Flashback
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At the time, it seemed like a great idea to bid on that motorcycle in North Carolina, but now it's time to pay the piper. You've been on the road all night, and I-95 is a desolate, lonesome road. Every station is playing lonesome cowboy songs, and you're exhausted and lonely. Drained, you're about to give up and find a motel to crash at when you remember that chick from college who lived in Charlotte...or was her name Charlotte? That part's fuzzy, but ten years later you could make a scale model of her body with chewing gum, if asked.

At a funeral

Top 5 Places to Have a Sex Flashback
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You never met Uncle Bill, but you’re in Cleveland anyway. The service is long, the priest is unintelligible, and you’ve resorted to giving yourself paper-cuts with the bulletin to stay awake. In the exit procession, your eyes are glued to the ass of the stranger in front of you. You’re not having a sex flashback at your Uncle’s funeral, come on, you’re not a monster…You’re scouting for your next one. (Please don’t be a cousin. Please don’t be a cousin…)

Imaginations are awesome.

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