Bring 3/4 cup water to boil in heavy medium saucepan over high heat. Stir in couscous. Remove from heat. Cover and let stand until water is absorbed, about 15 minutes. Fluff with fork. Melt butter in small nonstick skillet over medium-high heat. Add banana and sugar and saute until banana is soft, about 1 minute. Cool. Using electric mixer, beat cream in large bowl until soft peaks form. Fold in cream of coconut and triple sec. Reserve 6 tablespoons whipped cream mixture for topping. Fold candied pineapple, couscous, and banana into remaining whipped cream mixture in large bowl. Divide mixture among 6 parfait glasses or dessert bowls. (Can be made 4 hours ahead. Cover whipped cream mixture and puddings separately and refrigerate.) Top each pudding with some of reserved whipped cream mixture. Sprinkle each with fresh pineapple and serve. Cream of coconut is available in the liquor section of most supermarkets.