It's the age-old question everyone has an opinion on: Can two people have sex without any emotional drama getting in the way? Some experts, like psychologist Suzanne Phillips, say no.

"Those who have acted on what is now termed 'friends with benefits' often end up as friends with complications – or not friends at all," she says in an article on PsychCentral.com

Phillips, who is based in New York, says when it comes to these types of relationships, men always seem to have the upper hand.

"For men there is a sense of self-reported success and it's not always the same for most women. Women see more distress," she told The Huffington Post Canada.

Phillips says the relationship itself, friends or not, also differs. Having short-term flings rarely ends up with two people still having the same expectations for one another. Women, she says, end up with regret, while men are more likely to let the relationship go. Her studies have also found that people in long-term relationships have more orgasms and end up having more sex.

But not all perceptions of friends with benefits show the negative side -- Hollywood, for example, isn't helping the cause. Blockbuster hits like 'Friends With Benefits' and 'No Strings Attached' both create idealized representations of how these relationships really work out, Phillips says. However, they could be more true to life than previously believed -- it is now rumoured that co-stars from each of those movies, Mila Kunis and Ashton Kutcher, are 'non-exclusively' dating.

See Hollywood's modern casual sex films ... story continues below

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  • No Strings Attached

    The first of 2011's casual sex flicks, No Strings Attached starred Natalie Portman and Ashton Kutcher as old friends who decide to start having sex. Will they get together in the end? We can't even guess.

  • Friends With Benefits

    Next up on the f**k buddy train were Mila Kunis and Justin Timberlake in Friends With Benefits. Was it a coincidence that the two stars of Black Swan would end up making basically the same movie? Perhaps, but if they were handing out Oscars in this genre, Kunis would be the one holding the statue.

  • Knocked Up

    Big burly guy meets leggy blond, and guess what? She wants to have sex with him, just like it would happen in real life. Katherine Heigl and Seth Rogan turn a one-night stand into so much more -- and we can't help but admit we sort of love it.

  • What's Your Number?

    A woman who's willing to admit she's slept with more than four men? We can get behind that kind of plotline, particularly when it involves Anna Faris and her ridiculous antics.

  • Love and Other Drugs

    This movie starring Jake Gyllenhaal and Anne Hathaway supposedly has more to it than some romps in the sack, but you don't get that from this trailer. So we'll just pretend that these two good-looking actors spend most of their time onscreen in bed, without any attachments at all.

  • The People I've Slept With

    The lesser-known The People I've Slept With is a bit grungier than the more mainstream Knocked Up, but it follows a similar premise -- have casual sex, get pregnant, feel badly about your sex life. It does, however, seem to follow a more nuanced path.

  • Bridesmaids

    Kristen Wiig's Bridesmaids may ostensibly be about the nutty antics of getting married and the women that make it even crazier, but one of the best storylines has to be around Wiig and Jon Hamm's terrible casual sex relationship.

And casual sex isn't just casual sex any more. A University of Ottawa researcher says young people have their own codes to describe sexual encounters outside of committed relationships by using phrases like, "one-night stand," "booty call" and "sex buddy."

"We now have names to describe these things in ways that wasn't the case say 20, 30 years ago," said Jocelyn Wentland, a doctoral student in experimental psychology.

But despite all possible roads to failure, some say these relationships can work. College Candy, a popular site for young people, says keeping it carefree and fun, being honest with yourself, and making sure to consider your casual relationship a short-term situation are all ways to be successful at casual sex.

What do you think? Can friends with benefits ever just be about sex? Let us know in the comments below:

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