The funny thing about cartoons of grown men getting spanked is that I don't find them funny. I do find them very interesting for other reasons. Rare as they are, they do crop up occasionally--I remember Li'l Abner was spanked for the enjoyment of Sunday comics readers from time to time, though mostly off camera, as was Jethro on the Beverly Hillbillies, always off camera.
In my youth, when I would occasionally come across a cartoon featuring a man getting spanked, my excitement can scarcely be described. Although I don't find such cartoons funny, I think the fact that some men do is very hot for some reason.