Researcher Michael Smith allowed himself to be stung at 25 different places of his body by honey bees, and discovered that where you are stung determines show painful the sting is. The three least painful locations were the skull, middle toe tip, and upper arm, all scoring a 2.3 pain rating on a 1-10 scale. Some of the most painful places to be stung were the penis and upper lip, scoring 7.3 and 8.7, respectively. The nostril was the most painful place to be stung, scoring 9 out of 10.
This is a dedicated researcher! Sounds like very painful research. Best not to get stung at all.