When one posts something on Facebook or another internetblog site it becomes offical. The reasoning is that one posts information on the internet for all to see leaving little doubt that it didn't happen. Mostly used in the context of dating.
When you want to be Facebook Official (FBO) and you are sincerely in love with them and want the world of Facebook to know. Facebook Official Front Page aka FBOFP means you are wifed up
They have been dating for 3 years and he doesn't even cheat on her, no wonder they are Facebook Official Front Page (FBOFP). I bet they get married soon!
As almost all teens are addicted to facebook these days, a relationship is only legit if it is facebook official: when you update your status on facebook to "in a relationship"; its a huge-o slap in the face when you're supposedly dating someone but they don't make it known via facebook
Girl to her boyfriend: "we aren't facebook official! Do you wanna break up or something? Are you ashamed of me?!" Boyfriend: "god jenny you're so hormonal!" (for further usage, visit your local high school)