In a very large stock pot, bring a large amount of water to boil. Place crab legs and corn in the pot of boiling water. Boil until the corn is tender, and the crab legs are opaque and flaky. Check the corn and crab every 5 minutes to see if they are finished cooking. When finished cooking, drain well. Crack the crab legs with the back of a knife or a nutcracker to make it easier for your guests to get to the meat.
In a large saucepan, melt butter or margarine, garlic, chilli flakes and seasoning. Stir in the crab and corn, and saute for 5 to 10 minutes.