Wrestler24:
Wow. A lot of outrage from people who read and write erotic stories featuring boys and girls being spanked on their bare bottoms.
Well, I don't preceive it as "outrage," rather it's people making it unmistakably clear where they stand on the issue--remember that members of this Library will overwhelmingly tend to sexualize spanking so that in punitively spanking teenagers we'd be engaging in sexually-oriented (to us) activities with minors.
Also, when I produce a story about a teenager or preteen child being spanked, I virtually always fantasize being the spankee--not the person (usually an older child or adult) doing the spanking--and I'm figuring that many other writers, probably the vast majority even, have similar perspectives.
So AFAIC this isn't a situation in which a large number of people are fantasizing about spanking the bare bottoms of teenagers and children, in some cases pretty severely, but then are afraid to engage in these activities or even a milder version of them (moderate spankings on the seats of pants/skirts), thus fullfilling their desires in RL.
As someone else mentioned, playful birthday spankings of younger children are something different--I see no problem with doing that with parental approval, as long as the child accepts it as simple fun as well.
As for watching an adult (relative/friend/neighbor) I was visiting spank his/her child, I wouldn't interfere with or comment upon that parent's choice of discipline. I'd offer to leave, but if the parent wanted me to stay (considering the discipline merely a brief interruption in what we'd been doing) I very likely would although I'd almost certainly want to leave the room for the duration of the discipline. (The only exception might be if the child were being punished for a direct offense to my person and the parent therefore insisted that I observe "justice being done.")
It is important to remember that most people don't sexualize disciplinary spankings of children, the great majority of those who spank their children do genuinely feel that it's in the children's long-term best interest and I wouldn't want to appear to be judgemental about that--even if I wouldn't ever do it myself due to the sexual element that I would perceive in the act of punitively spanking a child.
But again, I'm reasonably certain that the overwhelming majority of writers who are describing teenagers and/or children being soundly walloped on their bare bottoms, generally by adults and/or older children, aren't visualizing themselves swinging the paddles, hairbrushes, straps, etc.--they're visualizing themselves yelping, kicking and crying... --C.K.