A word used to describe the various hook-ups and interchanging relationships that happen within a friendship group.
fred: didnt george just kiss mary yesterday?
chris: yup. And she broke up with dean last week.
Fred: but dean was with harriet?
chris: nah they broke up months ago. Jack is with harriet now.
Fred: yeah. I guess with all our friends hooking up you could call us frincestuous.