That sneaky look over your shoulder to see if anyone just heard (or smelled) your fart.
Having eaten too many beans for breakfast, Michael let out squeaky fart just before the opening hymn at church. A fartive glance at the old lady behind him indicated that she had heard and smelled his squeaker, and she was not impressed.
Often confused with a furtive glance the fartive glance is one of a more guilty standpoint. After one "cuts the cheese" in a public space, there is often a look on the face of the cheese cutter of embarrassment, as they look around to make sure no one heard/ smelt the passing of gas. The fartive glance can also be a glance of pride, if the cheese cutter is particularly pleased with how he or she cut his or her piece of cheese.
During the staff meeting, after the advertising department went out for enchiladas, Bob was significantly bloated. As the dean of the school was presenting his power point, an enormous fart cut him off mid sentence. Everyone looked around the room and immediately noticed the fartive glance on Bob's face.