YCSO - abbreviation for : "you can suck one," (referring to a penis).
Used in a text, just to tell someone to suck it.

texting*
Boss-"FYI, you need to have this work completed by Friday"
Employee- "Hey, I can make abreviations too; YCSO!
Boss- "What does that mean?"
Employee- "Look it up on urban dictionary..." (You can suck one)
by Taylor The Man September 12, 2011
Get the YCSO mug.