The term "exotic dancer" is a
euphemism for any kind of dancer who does things the
audience wouldn't want to see their
daughter doing (well maybe some of them would like to see their daughter doing it, but those few probably need to be
locked up anyway).
The term exotic is a synonym for foreign, and exotic dancers were originally women who "toured" a route arranged by a group of brothels or houses of ill repute, staying about a week in each place but moving on before any of the customers noticed they had VD. The women doing this were basically owned by the cartel of pimps, who kept them moving around the country and carefully poisoned their name after they left so they could never return.