妾

illegitimate (e.g. born to a mistress)

foreigner's mistress

house in which a mistress is kept

male paramour

serving as a concubine

one's wife and mistress(es)

Westerner's mistress

beloved concubine

(the most thrilling relationships for a man are) another man's wife, a maidservant, a mistress, a prostitute, and finally his own wife

keeping a mistress (concubine)

illegitimate (e.g. born to a mistress)

I

concubine

beloved concubine