In a medium bowl, whisk together the olive oil, lemon juice, honey, Dijon mustard, parsley, crushed red pepper flakes, salt, and pepper. Set aside.

In a medium saucepan, bring water to a rolling boil. Stir in couscous and a pinch of salt. Cover the pan and remove from heat. Let stand for 5 minutes, then fluff with a fork.

In a large mixing bowl, combine the fluffed couscous, arugula, cucumbers, cherry tomatoes, corn, and feta. Drizzle the dressing over and gently toss.

Before serving, fold in diced avocado. Serve warm or at room temperature.