Sort-of an ex

I've noticed that my twenties-somethings friends and I, who haven't settled into a relationship have reached something of a semantic quagmire when describing those people we are no longer seeing. What do you call someone you dated for an extended period of time, but never considered a "girlfriend" or "boyfriend?" How do you convey to someone in a title that you spent more than just a few dates with them, but were never "together?"

Mike likes to call them "ex's" because it he feels like it resonates better with his target audience (women) than when he describes the person as, "this girl I used to bang." I can't fault that logic -- no argument there.

Another buddy, who I promised would remain nameless, also likes to call them "ex's" because he feels like it makes him sound like less of a commitment-phoeb by having a recent ex -- he just leaves out the part that they broke up because he didn't want to get into a committed relationship with the girl.

Personally, I've been leaning towards "sort-of an ex." I feel like "ex" is a term reserved for those who held the position of "boyfriend" or "girlfriend" -- kind of like how Presidents and Generals always get to keep their title. However, in my book, if she didn't put in the full service time, she hasn't earned the title. I figure if I use "sort-of an ex" and follow it up by looking a little sad (and maybe breaking eye contact for a bit) I'll never need to really explain what it means.