What is a hook up? There are a lot of things that a hook up could be. It could be a one night stand, an ongoing NSA relationship or a friends with benefits kind of thing. It is perhaps more easy to define what a hook up is not. It is definitely not any sort of committed relationship that requires obligation or any of that messy relationship stuff. Hook ups can include traditional sex, blow jobs, make out sessions and anything under the sun. Sometimes kinky people call hooking up a play date while other people just enjoy the feeling of having sex with a friend with no relationship obligations!