FML - When I first saw FML, I thought it meant f*** myself laughing, and didn't get it. Then I thought maybe it was a reference to situations where you laugh because the only other option is crying. (I still think this kind of makes sense, but I know what it actually means now. :P)
OTP (One True Pairing) - This one's more a question, relating to people talking about their OTP(s) in fandom.* Can you only ever have one OTP, or at least, only one at a time? Or can you have different OTPs for different things? (Because wouldn't the latter defeat the purpose of having a ONE true pair?)**
I have to confess, I kind of love acronyms, although there are only a few I use, and sometimes just for fun. My favourite one currently is TMI (too much information).
* I really like the word "fandom" - I think it's because it could be the name of some faraway land. (I maybe perhaps should be in bed...)
**This point may or may not have been influenced by Prince Henry's ramblings about fate and true love in Ever After...