A ffasa stands for a "Far From A Sweet As". It can be used as an exclamation or used as an adjective. It is used to show obvious disgust or displeasure at someone or something, possibly an unfavorable outcome.
The word is said "Fasa" even though there are 2 Fs, you would sound stupid saying "F-Fasa". Not cool you fucking tool.
*Sergio* You know we got all that work to do for next week?
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi