A frelationship is when two friends start dating, but instead of acting like they are in a relationship nothing really changes between them. These situations usually end with one of the two actually starting to have feelings for somebody, thus the frelationship just goes back to a regular friendship. There isn't a messy break, because there never really was anything in the first place.
Cassidy: Are you and Dane going out?
Emma: Yes, but it's not that serious.
Cassidy: So, it's more of a frelationship then?
Emma: Exactly.