During the Battle of the Bulge, when asked to surrender, US General McAuliffe answered with the single word "Nuts!"
I know that "nuts" can be a crude way to refer to testicles ("He got hit in the nuts by the baseball") but I've always thought of the exclamation ("Aw, nuts!") as anodyne. Would a kid saying it in the 1940s have had his mouth washed out with soap?