The exact opposite of friends with benefit. It's like having a girlfriend but with all the bad parts and none of the good parts. You go through all the boyfriend/girlfriend drama and there's no making out, no hugging, holding hands, NONE of the good stuff. The worst possible relationship you can have with a girl, worse than being in the friend zone.
Jon: Yo, where's Michael at?
Alex: He's back there with his not-girlfriend, they're arguing about something.
Jon: Offff course they are.
The things you earn when you successfully flirt, ask out, or other things that involve people of the opposite sex. It's not a good thing to have to many, as that means you are a whore, or to little, as that means that you suck at getting some. It's most important to get right in between the two and stay around there.
Ask a girl out, get player points. Flirt really good, get player points. Easy.