By Joseph Wilkes & Bethany Whittingham Alison Hammond was left red-faced after a ‘fit’ supermarket cashier turned her down. The This Morning host confessed to the embarrassing proposal mishap on Rob Beckett’s new Sky panel show, Smart TV, where she serves as team captain alongside Josh Widdecombe. Each week, they and their celebrity contestants discuss top telly picks and answer trivia questions. Since joining the programme at the beginning of the month, Alison has shared a few cringe-worthy tales. However, the episode aired on Saturday night (April 13) might take the cake when she revealed a …