What is Nippelwetter?
1.
A physical nipple reaction caused by cold weather or sexual excitement. A german word meaning "nipple weather", originating from when girls in Germany would come out of a steamy disco into the cold weather and their nipples would get hard.
man to another man after seeing a girl with hard nipples: "Hey today is Nippelwetter"
or
woman to another woman with hard nipples: "hey you have nippelwetter"
See