Sellotape Sisters, playing this week at the Tristan Bates Theatre in Covent Garden, gets off to an inauspicious start. Ethel and Phyllis, played by Charlotte Weston and Kellie Batchelor, are in the dressing room before performing the last episode of low rent soap opera Sellotape Sisters. Weston and Batchelor exchange some semblance of witty repartee, …