The NCBI did a study on long term relations and one night stands and has come to the conclusion that the "booty call" is a type of relationship in itself. Their research shows as follows: "Most research on human sexuality has focused on long-term pairbonds and one-night stands. However, growing evidence suggests there are relationships that do not fit cleanly into either of those categories. One of these relationships is a 'booty-call relationship.'" Crazy to hear scientist using the term booty call isn't it? They continue below explaining the minor differences and nuances between those in a real relationship and those who are on a get in and get out mission. "Demonstrative of booty-call relationships' sexual nature was individuals' tendency to leave after sex and infrequent handholding. In contrast, the romantic nature of booty-call relationships was demonstrated through the frequency of acts like kissing. The results suggest the booty-call relationship is a distinct type of relationship situated between one-night stands and serious romantic relationships. So ladies were you taking notes? Frequent kissing means he really likes you. Leaving immediately after getting some and holding your hand once a week means you don't mean jack to him. Did we really need science to tell us this though? Source: (http://www.ncbi.nlm.nih.gov/pubmed/20672215)