Let's assume, for the sake of this discussion, that what I am about to suggest is perfectly normal for males and females to do and will not create any problems for you.
The next time you see a woman walking and her "boobs" are bouncing (doesn't matter if she is an A cup or a triple whatever cup), go up to her and ask her if she is wearing a bra, and then ask her to show you. I think you will be surprised that in just about every case, the woman with the bouncing boobs will probably be wearing a bra (as unfortunate as this is).
My point is, ALL BREASTS BOUNCE whether the person is wearing a bra or not. It is normal and healthy. And, while it may be true that not wearing a bra may cause the breast to bounce more, so what. Bounce is bounce. Plus, not wearing a bra firms up the coopers ligaments and to a certain degree the breasts, so that over time, the breasts will tend to bounce less. But, the point is, there will always be some bounce.
If a woman's breasts do not bounce when she walks, they are either wearing a very heavily padded bra (unhealthy), strapped down so tight that the person would be unable to take a deep breath (ouch) or had implants that make the breast so firm that they could use them as weapons (double ouch).
So give up on the bounce issue. It proves nothing.