Casual relationship
relationship without commitments
A casual relationship is a relationship between two people. It is very similar to a romantic relationship. People may have sex or a near-sexual relationship.
In a romantic relationship, people usually expect exclusivity. There will be only one person the other person has a commitment to. In a casual relationship, this is not the case.
This kind of relationship is often found among young people who want to try out new things but without committing to a particular partner. Such relationships often include casual sex, which means having sex with someone, outside of a romantic relationship.
Other words for this kind of relationship are casual dating, friends with benefits, hookup, and situationship.