To flirt with somebody overtime on Facebook because your both too shy to break the ice. Flirtbooking starts with clicking "like" on all of their post's, then comments on it to saying pictures of them are cute. Eventually you're drunk and message them at 2:46 in the morning.
Yeah I met Sara at the bar a few weeks ago but I'm not sure if she's into me so I'll just flirtbook with her and see what happens.
a flirtatious wall post on Facebook
Some random friend of Matt's just totally liked all of my bikini pics on flirtbook.