These slang words, when fully sounded out, mean "F-U-C-K Y-O-U"
Some people write, draw, or text this sentence to someone just because they are scared of fully just saying "fuck you."
And most adults, supervisors, or teachers wont notice it. They would this its just some funny slang for no reason or another.
Guy 1: "Too bad, Gerald! You missed the party! It was awesome, oh boo ho!"
Guy 2: "You know what? Eff You See Kay Why Oh You!!"
A long version of OMFG. This longer version is usually used to express an "over the topness" about things. Used in one of two ways. Either sarcastic in nature, or absolutely shocked and amazed. Sometimes this is used when someone says something which - in their mind - is awesome or shocking, but to the respondant, is quite the opposite. On the flip side, sometimes this is just "HOLY SHIT!!!!" type levels of shock and amazement. Either works.
Person A: "I walked my dog today!"
Person B: "OH EMM EFF GEE!"
or
MMORPGDUDE: "We took down UberBossFace!"
MMORPGHOMEY: "OH EMM EFF GEE!!!!!!!!!"
Ay bee see dee ee eff jee aitch eye jay kay elle emm enn oh pee queue are ess tea you vee dubeu ex why zed. Now I know my ABC’s. Next time won’t you sing with me?