IG

1- I Guess
2- Instagram

1-
Girl: Wanna hangout?
Guy: Hmm, Sure IG
2-
Guy: What is your ig?
Girl: skyler374

leecher

Most of the leecher is getting cracked things, like cracked action/fraps/sony vegas/hacks for games and more

leecher: Just found sony vegas cracked!
guy: tf u leecher

hoay

Short version for How old are you?
People using that when they don't know age of other people.

Guy: Hoay?
Guy 2: I'm 69 years old

Whos

slang of "Who is"

"Guy: "Whos listening to lady gaga?
Guy 2: "me!"

KYS

Easy and short way to say "Kill yourself"

K = kill
Y = your
s = self

Gay: Have you heared justin bieber - sorry?
Guy: kys, gay.