Those bounce way too much and way too fast. With such huge boobs, such fierce jiggling would be very painful. The movement would fit a piece of machinery, like a pump, better than boobs. The way the girl moves would suggest that the boobs wouldn't bounce so much in an up-and-down motion but more in side-to-side one.
Because I like boobs that bounce like something that is made up of fatty tissue and not rubber (or flubber, now imagine boobs made of that).
Otherwise the movement is rather hypnotic and it's well done despite the small size.
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