Many people have got into a casual relationship with a friend, which offers the no-strings-attached physical aspects of a relationship without the commitment and emotional vulnerability of a real relationship.
But sometimes these relationships do not run smoothly, as boundaries become blurred or one person develops feelings for the other
A study by Michigan State University asked young men and women about their relationships, according to the New York Times.
It was found that 60 per cent of people had experienced a 'friends with benefits' relationship.
But only ten per cent of these people said it developed into a romantic relationship.
A third of those who had had a 'friends with benefits' fling had stayed friends after the sexual element ended, while 25 per cent had not remained friends afterwards, reports the Cornell Sun.
Respondents cited a dislike of the commitment of a full-blown relationship as their reason for getting involved with a friend, as well as the chance to get intimate with someone without the emotional attachment.
Barbara Jastran, a therapist, said of these relationships: "Getting physically and not emotionally involved can be appealing because often, it takes work and time and involves emotional vulnerability to develop and maintain a healthy relationship.
"Some people who engage in 'friends with benefits' feel that they may be able to have sex and have it not be more than that."