Not Actually Laughing But That Was Funny. Its basically saying lol, but you aren't actually laughing
Sheryl: My mom just fell on a orange peel
not actually laughing but that was funny. instead of "lol" when you aren't really laughing, use nalbtwf. It just makes more sense.
(term created by E. Warshof and E. Wend)
boy: why did the chicken cross the road? Girl: why? Boy: to get to the other side! Girl: NALBTWF