Its a take on the term "blah blah" which we use when we are tired of hearing the same bullshit over and over again in real life. fblah fblah is basically being sick of hearing someones self riotous self help rhetoric they post on Facebook
I used to enjoy following this person on facebook until she broke up with her boyfriend now her posts are so boring just a bunch of fblah fblah.
by BrandtJohnson August 14, 2016