For use as word, not typed, pronounced ' Roffle-May-Oh', use in speech. Effect is lost in text conversations. Mocking tone, use is ironic, allusions to those who use 'ROFLMAO' literally, as this is not cool.
1b. Butting into another's conversation to mock them, when they are having a conversation about something they think is hilarious but is in fact, not funny AT ALL.
1a. Cool Person A: Why did the chicken cross the road? TO GET TO THE OTHER SIDE!!!
Cool Person B: Er... ROFLMAO.
1b. Geek A: I saw a totally RANDOM squirrell!
Geek B: OH MY GOD!
(Both GEEKS laugh)
Cool Person: (butting in) OH MY GOD ROFLMAO!