The small area of skin in between:
a mans testicles and his asshole, or
a females vagina and her asshole.
It contains a dense number of nerve endings hence it is extremely sensitive. It is a particularly good area for fondling and licking between lovers or oneself
an actual radiant ball of sunshine, too pure for this world, everybody wants to date her but nobody is good enough from her. very good at taking care of her cats and picking out gifts for her friends!