寵妾滅妻

favor the concubine and do away with the wife (idiom) / spoil one's mistress and neglect one's wife

to love / to pamper / to spoil / to favor

favored concubine

concubine / I, your servant (deprecatory self-reference for women)

to extinguish or put out / to go out (of a fire etc) / to exterminate or wipe out / to drown

wife

to marry off (a daughter)