 Carrie feels guilty like hell about sleeping with Big behind Aidan s back, but re-offends when he s out of state; while Big announces he wants to leave his wife for her, she looses Aidan s dog Pete. Charlotte s engagement-bliss whithers when Trey s family s  standard  prenuptial appears. Just after boasting how much better life is without a steady man, Sam experiences it s no fun being single with the flu. Miranda is very happy with a young new colleague, having a one nightstand followed by long-term phone-love as he returns to Chicago- till she finds out...