(n) A relationshipbased purely on the physical aspects, with no romantic involvement that occurs after hooking up with the same person for a minimum of two to three times.
Jane: "I hooked up with John last night"
Alice: "That's the fourth time in the past two week! You're totally in a fornicationship"
Ryan: "Dude the whole relationship thing is bogus. All you need in life is a good fornicationship with some chick"
Freddie: "Now that would be ideal"
An obligation to have sex due to pressure or circumstances. One may experience this when a friend is fornicating with their partner and you are alone with a person of the opposite sex your friend "set you up" with.
Guy 1: So what did you do last night
Guy 2: I went over to my bros house and he went to go bang his girl the whole night and I was left alone with my bros girlfriends friend