The relationship may or may not be exclusive, in which one or both of the involved parties interact sexually with other people.
Daytime relations between hookup buddies, similarly, can be close and active, or meeting to hook up can be their only contact. Those who hook up per the latter description often, but not always, rely on alcohol or other substances that suppress inhibition to facilitate the interaction.
All definitions purposely lack commitment, a term whose inclusion would define the pair as dating.
On college campuses and beyond, the designation "hookup buddies" is usually used by those not involved to imply sex, whether or not the parties spoken of actually have intercourse.
For many in the 18-25 age bracket, the status of hookup buddies is a comfortable medium between coldly platonic friendship and the out-of-date, restrictive, if secretly missed-by-some exclusive relationship. For others, a hookup buddy is equivalent to physical and/or emotional attention on demand, without the pressures of a formal relationship.
Girl 2: "Yeah, we hang out now and then; we're both too busy for a relationship though so I guess you could say he's a hookup buddy."
Girl 1: "Ooh, who's that cutie over there?"
Girl 2: "Oh that's Jason; he was one of my hookup buddies last year."
Guy 1: "Dude, are Steven and Becky dating?"
Guy 2: "No, I hear they're just hookup buddies."