This is a form of using some kind of sarcasm while making it funny but not too mean. It sort of means like gee, you think?
Kady: am i really going out with you tonight?
John: elemayo, should I check?
Simply a phonetic spelling of the term lmao or LMAO as if each letter was spoken out loud. Implies a more genuine sentiment of laughter where lmao is overused by others.
That was elemayo!