February 14th, a day to celebrate love and togetherness, a day to remember the beheaded Saint Vincent, who defied the orders of Emperor Claudius II in the third century and married young lovers in secret. Or, a day to dip the strips of sacrificed goat skin in blood and bless the town’s women with fertility with a “gentle” lashing. Red hearts, thorny roses, proclamations of undying love and sacrifice—indeed, it seems Valentine's Day is full of subtle (and not so subtle) cues leading us to horror, one drop of blood at a time. These cues are likely just one reason why people always ask me, “Is it really a good idea to bring a date to a scary movie?” And the answer, much to their frustration, is “it depends.”

Sex and horror have a long history, and the connection goes beyond filmmakers banking on viewers turning out to see slasher films featuring partially clothed women fighting monsters and serial killers. The lanes of sex and fear have often intersected, well before the sexual undertones of Dracula and the more explicit sexiness of Interview with the Vampire. (Check out, for example, The Curse of the Cat People, a movie from the 1940s about a woman from a family cursed to morph into killer cats when sexually aroused. It has all the high arousal stimuli the Internet loves in one movie).

Setting aside (though not disregarding) the less than empowering ways sex and horror have met in entertainment, let’s look at some of the reasons why, and how, this matchup can make for a sexy, fun time.

First, the basics: when we’re scared, our sympathetic nervous system jumps to action and gets our body into “go mode” so we can run or fight: our heart is racing, we’re breathing more quickly, adrenaline and endorphins are surging through our body, and that’s just the start (you can read more about that here and in my book). This threat response is what has kept us alive generation after generation. And, as every action and horror movie romance has shown us, the cascade of chemicals that our body activates in this state can have some very interesting influences on how we feel about those around us. Sometimes referred to as “glad to be alive” sex, it’s a common trope in horror and action films alike. Those of us who came of age in the ’90s will most famously associate this with the steamy exchange between Keanu Reeves and Sandra Bullock in the movie Speed, after they narrowly escape a runaway bus about to explode.

But, it is more than movie myth; sex and stress, along with other “high arousal” states share a lot at the physiological level. Think about how you feel after winning a big game, climbing a mountain, or making it through a haunted house—you’re on fire, energized, feeling fully awake and even a little primal. Add an attractive potential sexual partner into the mix and, well, that energy can shift in a whole new direction, provided you’re not actually in real danger.

This is also why make-up sex can be so great; the fight is over, trust is restored, and you’re left with bodies that are all revved up and ready to go. But pump the brakes before you go out looking to recreate passion under fire, because you could get horribly burned.

Yes, the “misattribution of arousal,” or the tendency to attribute the feeling of excitement to the person you're with, rather than the monster on the screen, is a real thing. This phenomenon was famously tested by Donald Dutton and Arthur Aaron by having unsuspecting male subjects walk over either a very scary suspension bridge, or a not-so-scary normal bridge before completing an interview with an “attractive” female. They found that the men who experienced the high-anxiety-inducing suspension bridge were more likely to engage with sexual imagery when asked to write a story, and more likely to call the female following the interview. The theory goes that when we’re in a state of heightened stress, aka high arousal, we find people more attractive—either because we think the person is responsible for getting our inner fire ignited, or because our fire is burning and we’re ready to cook, so to speak.

But, it’s not a guarantee. For one thing, if you don’t find the person attractive, or worse, you feel threatened by them, watching a scary movie or even walking over a scary suspension bridge isn’t going to change that—in fact, it might make it worse. Just as your date can attribute their feelings from the movie to you in a good way, they also can blame you for feeling bad, and even get mad and defensive, leading to one silent and uncomfortable ride home.

The major chemical component studied in this interaction is oxytocin, the one you might hear a lot of people refer to as the “love hormone,” because it has been shown to promote social bonding and increase feelings of connectedness. But, oxytocin is also released in times of stress and animal and human studies show that it can promote the exact opposite of love, meaning it may increase aggressive behavior. A key difference is linked to underlying personality traits (like if the person is prone to physical aggression) and context (a mom protecting her pups). My two cents: save the horror movie for a little later in the relationship, when you know you’re both into each other and up for some sexy scares. You want your date to see you as a partner in crime, not the criminal.

So, yes, doing something exciting, scary, and even a little dangerous can increase the intensity and make for one heck of a sexy evening—but before you drag your unsuspecting partner out to the latest horror flick, (like Fifty Shades of Grey, which is a horror film according to those who actually understand and respect the principles of the BDSM community), find out if they even like horror, and if so, what kind. The sexiness of Jeff Goldblum and Geena Davis in The Fly won’t get through to your date if she’s grossed out by body horror, but a ghostly supernatural thriller might be the perfect prelude to steaming up the windows in the parking lot. Get scared, get sexy, but don’t forget the first “s”: stay safe.