This is an extreme insult, deriving from Northern Ireland, hence the spelling to emulate local dialects. It is in common use as a put down. It is accompanied by two or more fingers held together, as if inserting into an orifice, and waved under the victim's nose. It reflects the harshness and vulgarity common to N. Irish conversation.
Have you been done for University-wide corruption again, boss?

Smell yer ma, ye wee shite.
by docrob September 15, 2009
Get the smell yer ma mug.