flake up artist

Someone who is noncommittal or agrees to everything but then never shows up and therein flaky. So flaky to the point of being almost professional in the practice of it. A professional flaky person. Hence, flake-up artist.

e.g.

Ben: "Liv! We haven't met up in ages!! Fancy meeting up this weekend? I'll be in your neck of the woods any how so we should deffo meet up for a crafty drink! You down?"

Liv: OMG! Ben!!! YES. We gotta do this! Bell me when your here and I'll come down!

(24 Hours passes and Ben arrives at agreed location)

Ben: "Hey Liv, I've just arrived! Where abouts are you?

Liv: ...

Ben: "Liv? Are you en route??"

Liv: ...

Ben: Fml....