What is it about breast motion that some people find offensive? Here's a thought:
Basically, body fat is generally not attractive to most people. When body parts like thighs or arms jiggle, most people find it ugly, but when it's breasts, generally men find it a turn on (not all, but most - it's a brain wiring thing I think), but many women react the same way to them as any other jiggling body part - they'd just rather not see that.
I'm guessing even women who don't find breasts offensive consider movement something they ignore, if they notice it at all (unless they're the ones experiencing it - having nerve endings in them would be a different perspective than just seeing it happen).
Think there's anything to this thought?
From what I've heard and read over the years, it does seem a lot of people think breasts should be immobile globes devoid of any motion. This has never made sense to me. It is perfectly normal for breasts to jiggle at the least if not bounce and sway as a woman walks about and no one should find this natural movement objectionable.
But to show it's not sexist, I've heard as many disparaging remarks about the way unconfined male genitals swing and sway so it seems a lot of people just have a general bias against 'uncontrolled movement' of any body parts. I've never understood this, and in fact, I have always found such movement rather interesting to watch.