A terrible ripping noise

It started when Sandry was halfway down to the chair, she was unable to stop herself as she went the rest of the way down and the sound of tearing stitches intensified, until her backside hit the chair and felt colder than it should have.

"Oh, no." Sandry gasped.

"Oh, my." Robyn exclaimed.

"That's torn it." Sandry half-stood again, to show the back of her skirt to her friend, "How bad is it?"

"Well," Robyn replied, biting her lip...