The first time it happened, I thought it was a fluke.
The second time it happened, I was really glad I was done nursing.
By the 15th time, it became clear, AK needed to be transitioned off the bottle.
Baby girl sucks so hard, or so much, or whatever, that she creates a vacuum in the bottle and the nipple INVERTS. It actually goes from pointing up to pointing down, into the bottle. And sometimes the vacuum creates so much suction that the nipple actually pops out - inside out - into the bottle.
This never happened with LP. It happens almost every night with AK. And she gets pissed at me when I take the bottle away to fix the problem.
Yesterday we started weaning her from the bottle.