“Get a room already!” That’s the first thought many of us have when we see couples who can’t keep their hands off of each other in public—you know, like when a couple decides to have a full-on make out session in a movie theater, on the subway, or at a bar. When we see something like this happening, it can be hard to look away, even if we are a little annoyed by it.

So why do people perform these attention-grabbing PDAs anyway? Are they simply demonstrating their affection for one another? Probably not.

A new study published in the Journal of Sex Research suggests that most of these acts aren’t true “public displays of affection” because people usually have ulterior motives. In fact, affection is rarely the reason when it comes to why people decide to get all hot and heavy in front of an audience.

In this study, researchers surveyed 349 college students (most of whom were white and heterosexual) about their experiences with what they termed “performative making out.” Think of this as intense kissing—and maybe even a little mutual groping—that occurs in a setting where it’s going to be seen, such as at a party or in a club. Participants were first asked whether they had ever done this and, if so, to describe what it was like. Afterwards, they were given a series of follow-up questions about why they did it and the reaction they received.

What they found was that roughly one-third of the students had done this at least once before. Although women and men reported similar rates of performative making out overall, women were more likely than men to say they’d done it with a same-sex partner (eight percent versus two percent, respectively). Interestingly, whereas all the men who had publicly kissed other men were gay, virtually all of the women who had publicly made out with other women were straight. We’ll explore why in just a moment.

There’s a double standard for men and women who engage in performative kissing.

So what motivates performative making out? That depends on your gender. For men, the most common motivator for making out with a woman in public was to enhance their image or increase their social standing in some way—you know, to look like a player or to get bragging rights. Smaller numbers said they did it to demonstrate their relationship status (or make it clear that their partner is off-limits), to start a new sexual or romantic relationship, or to have fun.

By contrast, the most common motivator for women to make out with men in public was to cause envy or jealousy. It was usually an ex-partner that these women wanted to make jealous, with some hoping to exact revenge and others hoping that their ex would ultimately end up wanting them back. Less common reasons mentioned by women included demonstrating a relationship and enhancing their image.

Women’s motivations for public kissing were totally different when their partner was of the same sex, though. While women primarily made out with guys to make their exes jealous, they tended to make out with women for fun and games (think “truth or dare”), to gain status (by being perceived as uninhibited or adventurous), and/or to turn-on guys who might be watching (such as fulfilling a boyfriend’s lesbian fantasy). As you can see, there are a lot of reasons a woman might engage in same-sex kissing that don’t necessarily have anything to do with her sexual orientation.

So do people who engage in performative making out tend to be successful at achieving their goals? Again, the answer depends on your gender.

Men reported more positive than negative reactions. In other words, guys tended to get what they were after, whether it was looking better in the eyes of others, starting a new relationship, or just having fun. Only a few guys reported regretting the experience, either because it turned out to be awkward, someone’s feelings got hurt, or they got made fun of.

On the other hand, women reported more negative than positive responses overall. The most common negative outcome for women was harm to their reputation, such as other people thinking she was “easy” or a “slut.” This means that there’s a double standard for men and women who engage in performative kissing. Whereas men often get an image boost, women often get slut-shamed.

Overall, what this study tells us is that a lot of the behaviors we label as PDA aren’t really about two people expressing their feelings for each other. Rather, when couples are really going at it in public, what they’re usually trying to do is manipulate the feelings of those who are watching toward some desired end—most commonly, to make themselves look good, to piss off their exes, or to send a message that their partner is off the market.

Of course, performative kissing is just one way people might try to manage impressions of themselves and their relationships. Those who are a little shier and bit less exhibitionistic may very well have the exact same image concerns—the difference is just that they manage them through posts on their social media accounts instead of sucking face in public.

Justin Lehmiller, PhD is a sex educator and researcher at Ball State University, a Faculty Affiliate of The Kinsey Institute, and author of the blog Sex and Psychology. Follow him on Twitter @JustinLehmiller.