Its cold today, my nipples stick out like bing cherries.
Actually I stole that expression from Catch 22 when Yossarian and the other aircrew were fantasising about the general's assistant. Heller said that the nurse had nipples like bing cherries.
I didn't know what a bing cherry was but I got a hard-on thinking about that as I'm sure did every other 14 y.o. who was reading Catch 22 at the time.
I've since found out what a bing cherry is. Here's a picture of one:
My opening line was literary licence as my nipples are not standing out that much, but it is cold.
Why do nipples stand out when its cold?
I wonder if Richard (of RBB) knows?