Idk, could be that they cut of the outer layer to make it more sensitive? I don't know, this manga is weird enough.
(=°^°=)
I believe they just nicked the tips of the nipples while they were hard making them sensitive, and it doesnt hurt that bad.
Have you done it before, how do you know
Interesting....
Yea lol ab two times and it does heal it takes a few days to a week depends how ur nicking off
Not the nipples what exactly was nipped off?? Skin? Does it like... grow back? Ouch