“Welcome aboard Southwest Flight 245 to Tampa. To operate your seat belt, insert the metal tab into the buckle, and pull tight. It works just like every other seat belt, and if you don’t know how to operate one, you probably shouldn’t be out in public unsupervised.”
Okay, sure, seat belts are pretty intuitive, but the belts on planes are not exactly like the ones in cars! Cut the passengers some slack. Or, rather, let it out by pulling on the buckle.