2) slang term for the anus
2) Blow it out your ying yang, dickhead!
Use of "ying yang," or "ying-yang," has seemingly allowed the word to take on a kind of "sing-songy" resonance with the additional "ng" sound placed on the end of "yin."
For many, it has become second nature to say "ying yang" instead of "yin yang" because of familial or cultural influences, such as family, friends, and teachers. This may stem from simple ignorance, within certain groups, of Taoism (pronounced Daoism) and other Eastern traditions.
Mary: *sigh* It's a yin yang...
Susie: Yeah, ying yang!