Cook beans according to package directions. Meanwhile, in a skillet, cook bacon, onion and green pepper over medium heat until bacon is crisp and vegetables are tender. Remove with a slotted spoon. Stir the flour, brown sugar, Worcestershire sauce, salt, pepper and mustard into the drippings until blended. Stir in tomatoes. Bring to a boil; cook and stir for 2 minutes or until thickened. Drain beans and add to skillet. Stir in bacon mixture.