IStock Photo 11519795 © Orange-Melody

Of all the pop culture representations of “friends with benefits,” Monica and Chandler might have made it look the easiest. On “Friends,” those two hopped into bed after years of platonic buddy-hood, briefly kept it casual, and then lived happily ever after. Research shows that this is unlikely in real life—off-screen, only about 10% of friends with benefits (FWB) turn into lasting romances. And anyway, since sex-with-no-commitment is what appeals to a majority of FWB participants, the Monica/Chandler resolution might be more nightmare than dream come true. For undergraduates and twenty-somethings, habitually strapped for time and money, the absence of dating as a prerequisite to sex sounds ideal. Sure enough, the friends with benefits relationship has become ubiquitous, especially on college campuses—but when it comes to sleeping with a pal, the morning after is rarely as straightforward as the night before.

If you haven’t done it yourself, you probably know someone who has. The odds a college student has ever had a friend with benefits are 1 in 2, with men more likely than women to report such arrangements. Among male undergraduates, the odds are 1 in 1.57 (about 64%), while for women, the number is 1 in 1.99. The rationale behind acquiring friends with benefits is rather unsurprising. Melissa Bisson and Timothy Levine, who conducted a study of FWB relationships at Michigan State, found that sexual involvement with a friend was viewed as safe and convenient. There’s also the comfort factor: many young people prefer to have sex with a person they know and trust, rather than that cute stranger at the bar. So an FWB situation is a happy medium between an actual romantic commitment and a casual hook up.

Isn’t it? Possibly not, says sex educator Yvonne K. Fulbright. Fulbright argues that a big problem with friends with benefits is that communication within the friendship itself breaks down. Bisson and Levine, too, found that about half of all FWB participants at Michigan State reported uncertainty about the relationship, and a majority of these said that those concerns were not addressed.

There is also the risk of one person developing more intense feelings for the other—the omnipresent threat of “wanting more.” Popular wisdom suggests that this is the biggest pitfall of friends with benefits, and indeed, about 81% of the respondents in the Michigan State study cited the development of romantic feelings as a key disadvantage.

Someone might get jealous, too. Even though there’s no official commitment, it can be hard to see the person you’re sleeping with flirting with someone else. The odds an undergraduate describes him- or herself as a jealous person are 1 in 1.79 (about 56%), and a large-scale study published in the College Student Journal found that students who described themselves as jealous were more likely to have friends with benefits than those who did not. While this might seem contradictory, perhaps it reflects a tendency for jealousy-inclined young people to avoid the challenges of committed relationships—or maybe the FWB precedes the jealous feelings, with the peculiar dynamic of a sexually involved friendship drawing out the green-eyed monster.

Either way, the research (and common sense) suggests that the friends with benefits scenario has its risks. In the end, one in four FWB relationships ends with both the friendship and the sex broken off, and a third call off the sex—presumably when things get complicated—but manage to salvage the friendship. So sure, you can buy a t-shirt promoting friends with benefits, or find rules of the game online, but once you’ve hopped into bed with a friend, getting out can be much more challenging.