So any mom's breasts feed with nipple rings?

You have to take them out, it's a choking hazard.

But can I put them back in after?

Yes, you can put them back in after, you just don't want to have them in while feeding.

Take them out during feeding, put them back when you're done. But you have to remember to take them out every time you feed

They'll prob be so sensitive you won't want to put them back in lol