A friends with benefits relationship can be tricky to define. Usually, friends with benefits (a.k.a. FWB) means that people who know each other engage in intimate/sexual activity without really dating each other. Its different from hooking up, which tends to be a one-time thing with someone new.

Is it friends with benefits or a relationship?

Friends with benefits relationships (FWB or FWBR) is a term commonly used to reference a relationship that is sexual without being romantic. These non-committal relationships can be short term, or evolve into serious romantic relationships.