This article is controversial and it will be based on my opinion.

Once they get to a certain age even if it is completely unnecessary.

It’s not ‘socially acceptable’ for women to wear bras. Bras are very uncomfortable, after all. It’s just socially acceptable for women not to show the shape of their nipples through a thin top. You could be an AA small bust but this will still be necessary because female nipples are sexualised and small boobs still have them.

So this would be socially less acceptable even though she’s small:

I have 100’s of bras, and pick one from my collection to wear…once a month. Just because it lifts you up a little and looks quite pretty with all those patterns and frills and makes you feel good, even if no one else will see it.

But lets face it, they’re very uncomfortable. Even the lacy ones with less padding, because what’s with all those straps, someone NEEDS TO INVENT SOMETHING MORE PRACTICAL.

But don’t despair, if you don’t want men to stare and women to turn their noses up, and you’re anything below a C, you can easily get away with these, which I wear all the time to avoid social suicide:

Or try frilly tops or tops with inserts so nothing peaks out

Source: http://socialspy.ng/2016/08/10/why-is-it-socially-acceptable-for-all-girls-to-wear-a-bra/