GFY has 2 meanings
Go f*** yourselfCensored
If you make someone really mad online, they might tell you to GFY (go f*** yourself). This request is not meant to be taken literally. Instead, it is intended to function as a more crass version of LMA or GALMA.
When someone tells you to GFY, you likely should not continue to engage them. Instead, log off, take a break, and just chill for a few minutes.
Yeah, well why don't you GFY?
|GALMA||Go away, leave me alone|
|LMA||Leave me alone|
|DBMN||Don't bug me now|
|IHU||I hate you|
|PITA||Pain in the a**|
|WIYP||What is your problem|
|IHY||I hate you|
GFY stands for "good for you." This acronym is another way of saying "nice job," "great," or "way to go!"
While GFY is typically used in earnest, friends and frenemies alike may also use GFY sarcastically. For example, if you tell a friend "I was attacked by a giant octopus," and they send back "GFY," they most likely are not actually excited for you.
In other cases, GFY may be used to express jealousy. For example, if you are lucky enough to inherit some money, and you inform your less-financially-well-off friends, they may respond with a slightly jelly "GFY."