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!"
MMORPGDUDE: "We took down UberBossFace!"
MMORPGHOMEY: "OH EMM EFF GEE!!!!!!!!!"
Getting absolutely, totally, completely annihilated during homecoming festivities. A whole helluva lot of alcohol and/or drugs are most certainly involved. This can (and very often) result in one or more of the following:
Dizziness/Loss of balance
Waking up in a random location
Random cuts, bruises
Ending up getting intimate with a complete stranger (or two)
Making a fool of yourself and ending up on Youtube/Facebook/etc for all of eternity
One might say "oh so you just got fucked up then?" No. Getting "homecominged" is "fucked up" multiplied by about a billion.
"I woke up in the middle of Aberdeen wearing nothing but fuzzy slippers and an inner tube. Apparently I've got lipstick on, and I'm a guy. My ass got homecominged."