In medium saucepan, bring water to a boil. Stir in couscous. Cover; remove from heat. Let stand 5 minutes or until liquid is absorbed.
Meanwhile, in medium saucepan, combine spaghetti sauce, beans and red pepper flakes. Cook over medium heat for 5 to 7 minutes or until thoroughly heated, stirring occasionally.
Fluff couscous with fork. Serve sauce mixture over couscous; sprinkle with parsley. If desired, sprinkle with shredded fresh Parmesan cheese.