SOCIAL: WHAT IS A "FUCK NOTE"?

A "fuck note" is a memorandum that a person is sent a "message" that an invitation to treat is calling him or her to address a need or a want.  "Fuck notes" are often given to people when the scenario ends.  Its the last message sent to another depicting interest.  This could mean that a person is dismissed in a place of legitimacy.  "Deviance" is always a subject of contention and it serves to push the boundaries.  More often than not, operating via deviance means that legitimacy is implicated in favour of pleasure and the deviance cannot occor in the place of mutual legitimate cooperation but must occor in a place of mutual self interest.  I wonder what "pleasure" is gained from "fuck notes"?