Edit much Magoo....
“I have no doubt I could give a stimulating talk that would stiffen the manly fiber of everyone in the audience,” Asimov responded. However, permission would need to be sought from those being pinched, and “if they say ‘no,’ it will be ‘no.’ Of course, I could be persuaded to do so on very short notice; even after the convention began, if the posteriors in question were of particularly compelling interest.”
Has the meaning changed?