So You Caught Your Date in a Facebook Lie -- Here's What to Do
Truth be told, I'm not really a huge fan of this kind of confrontation, though I do hate getting stood up for a dance party, which is always thinner than I am and has better hair. If he hasn't given you other causes for concern, it's difficult to bring up a Facebook foible such as this without coming off as kind of paranoid and insecure, especially now that the "evidence" is gone.
If you are determined to confront him, which is totally within your rights, you could ask him questions about his supposed family situation the next time you see him. It's usually pretty easy to tell when someone is lying in person. They fumble or pause or look around the room a lot, like a less-cute-because-of-the-lying spider monkey. Who knows? He might have a good excuse for blowing you off even if he was lying.
I'd give him a pass this one time, if it were me. Then I'd keep an eye out for general shadiness. If you notice that his lying is a trend and not a one-off deal, then you have my blessing to "check him into" The Dumpster, which is not an actual place but a metaphor for dumping someone.
Also, was your planned date super important? Or was it just, like, eating Birthday Cake Oreos and watching a Food Network marathon on the couch? Basically, is one missed date worth accusing him of treachery this early in the dating game? That's what I'd ponder before bringing Foursquare evidence into your love life. Especially if your other recent dates with him have been generally solid.
Speaking of online dating, did you read my review of Cupid Talks?