Young Scain's definitions
A facial expression expressed by a man or woman who has been discovered recently engaging in an illicit or private activity, usually appearing delighted.
Jason woke up later in the afternoon, and saw his house mate and some young woman on the couch roused and mussed up with grimey-ass grins on their faces.
by Young Scain June 23, 2007
Get the grimey-ass grinmug.