lol idk, but I do know spiro causes breast /nipple tenderness. IDK if the spiro would be the cause of the constant nipple pinch feeling, or if it's general breast / nipple development. If I had to guess, however, I'd go with the nerves in the nipples are growing and while doing so, they're much more sensitive to the touch than we're used to. I know mine don't generally hurt unless I push on them a lil.
I got turned on when I was showering and the water hit my nipple! I was like.. oo what is this?... now I smile more 😀