Turn grill ON and set to medium heat.
Place the corn on the grill; close to cover the grill and cook for 15 to 20 minutes, turning corn every 5 minutes, until kernels are tender.
Remove from grill and let stand 5 minutes.
When slightly cooled, pull husks away from corn and remove silk strings.
In the meantime, prepare the feta cheese and chives butter
In a mixing bowl combine butter, feta cheese, chives, red pepper flakes, salt and pepper; mash and mix until thoroughly incorporated.
When corn is ready, spread with the prepared butter mixture and serve.