Helen and Mark's relationship is stale. They rarely have sex anymore and, if they do, it is because Mark has instigated it. During those times, Helen just seems to go through the motions as though bored of what is taking place. Mark knows there is a problem but doesn't say anything. He just hopes that - one day - it will get better. Luckily for Mark, things do change. After an emergency visit to the dentist, to have a tooth extracted, Mark inadvertently stumbles across Helen's fetish...