At the bar, I watched a sickening scene unfold: a happy couple kissing.

This grotesque display of affection was disturbing for reasons beyond the tongues and the groping — it was the first time I realized public displays of affection aren’t always about demonstrating love. It was clear that this couple had ulterior motives for swapping spit before a disgusted audience. Thankfully, psychologists have figured out exactly what those are.

Affection is rarely the reason couples get nasty in public, says a study published in The Journal of Sex Research. For the study, the researchers talked to hundreds of college students about “performative making out” — intense kissing or heavy petting in a setting where partners know damn well they’ll attract attention.

Couples who engage in near-pornographic PDA do it not for their lovers, but for their audience.

Around one third of participants admitted to doing it, and then were asked why they did it, what it was like, and the reaction they received from onlookers. Women and men put on sexual shows at about the same rate, although women hooked up with same-sex partners significantly more than men did.

The motivations were very different for men and women. Men claimed that conspicuous kissing enhanced their image or increased their social standing. These dudes are essentially announcing to the world, “respect my sexual prowess as I pound my tongue down my girlfriend’s esophagus.”

A smaller proportion of men said they make out when surrounded with witnesses to demonstrate their relationship status — conveying that their partner is off-limits by exhibiting some sense of ownership. This can be a hit-or-miss move depending on what type of lady they’re dominating. Some don’t appreciate being publicly domineered. Others find it comforting, knowing they’re safe under some dude’s possessive protection.

“Fun and games” is another reason men say they’ll fondle their lady in front of others. Exhibitionism is a major turn on for tons of folks, and becoming a spectacle might arouse them even more than the person pressing on the bulge of their Wrangler jeans.

Women, on the other hand, had their own hidden motives. Most often, ladies swapped spit with men in public to make someone else jealous — particularly their ex. If they were getting physical with other women, though, the reasoning was less vengeful. Girls kissed girls for fun and games, to seem adventurous or uninhibited, or to arouse men who might be watching.

Women also mentioned motivations to flaunt their relationship status or improve their social status. Unfortunately, women were far less likely than men to get the outcome they’d hoped for.

Ladies reported more negative reactions to their PDA — typically damage to their reputation. Men reported the opposite. Instead of being slut-shamed, they were slut-celebrated.

The research proves that for both men and women, performative kissing is exactly what it seems — a performance. More often than not, couples’ public displays of affection aren’t about expressing intimacy for one another. They’re about manipulating the reactions of those around them.

Whether you’re getting groped at the bar or getting fucked on a Sunset Boulevard balcony, you’ll almost certainly get a reaction — maybe reverence, but far more likely revulsion.