Your girlfriend is planning a fancy dress party soon perhaps you could find something she would like. As you wander through the store you pass a bewildering array of costumes until your attention is drawn to a gleaming sliver mermaids tail. "One size fits all. Guaranteed!" boasts the label, "accessories included". Reading the label you feel a strange urge to put it's claim to the test. "Well why not?" you think to yourself "just for fun". There dosn't seem to be anyone about so you scoop up the tail and head for the changing room.