Friends With Benefits

Jamie (Mila Kunis) works as an executive recruiter for a leading job agency in New York city and Dylan (Justin Timberlake) works as an art director in Los Angeles, Jamie has to try and recruit Dylan to interview for a job with GQ magazine. He ends up accepting the interview and they spend time talking around New York City. Jamie presents the contract to Dylan the next day and they end up spending more time, and end up with the conclusion that sex should not come with any emotional or that many attachments. So they end up fooling around with each other and end up falling for each other in the process. 

There are few love theories that this movie displays first is Sternberg's Triangular Theory of Love and then continues with Lee's Styles of Loving.

First Sternberg's Triangular theory of love comes into play by they first showed intimacy, by having connectedness or bonding with one another, when they started to hang out and get to know each other. Then this led to sexual attraction, but without the "emotional attachments." and their decision to be nothing but friends with benefits was the label of their type of relationship.

Lee's Styles of Loving was showed throughout the movie, the were playful and not serious with each other and at first had a mutual relationship with each other. They depended on one another for sexual pleasure and desired the other person.  They had  Ludus type of love, carefree and casual, little emotional rapport and no committment.

But as usual as people spend more and more time with one another their is an attachment to them and a wanting. So after falling for each other they practice a more understanding relationship, one that might be more long term, to maintain their commitment over time, this going back to Sternberg's Triangular Theory of Love, in the decision/commitment component.