Happily Ever After? It's easier to talk about death than it is to talk openly about step-families. One in three marriages in Britain today is a re-marriage -in 90 per cent there are children involved. The main focus of social concern and advice tends to be on the children. But what of the five million step-parents? What are their difficulties and anxieties? MAVIS NICHOLSON talks to some of the experts (sociologists and psychologists) and to the step-parents themselves who speak out intimately and frankly and offer some encouragement to others in a similar situation. Written by BRENDA MADDOX Producer GAYNOR SHUTTE