Citations:stupid ass

1967: "Jacky" by Mort Shuman (performed by Scott Walker), translated from the French original by Jacques Brel and Gérard Jouannest
 * If I could be for only an hour
 * If I could be for an hour every day
 * If I could be for just one little hour
 * Cute in a stupid ass way

I haven't found anything earlier, though it's a tough search. The noun phrase obviously is much older than the adjective.