The participants of casual sex were named "f*ck buddies" by Owen Harper, who himself did "the f*ck buddies thing". After having sex with pilot Diane Holmes, Owen suggested that they have an affair and become "f*ck buddies". Diane, however, believed that there was nothing casual about their encounter. (TV: Out of Time)
Sex shouldn't be devalued. Both parties should give it one hundred percent concentration. Because when you take off together it's the next best thing to flying.