This is a parody on over-politeness. A young man is standing on a corner talking to a pretty girl, when a second man comes along and joins him. He notices what appears to be a bit of string or thread on the young lady's waist, and promptly attempts to remove it. Unfortunately, it is the thread from a seam in the young woman's skirt and as the young man persists in pulling, the garment falls apart, much to the young man's embarrassment and chagrin.