SB 10.61.23

yady apy anusmaran vairaṁ
 rukmī kṛṣṇāvamānitaḥ
vyatarad bhāgineyāya
 sutāṁ kurvan svasuḥ priyam
Word for word: 
yadi api — although; anusmaran — always remembering; vairam — his enmity; rukmī — Rukmī; kṛṣṇa — by Lord Kṛṣṇa; avamānitaḥ — insulted; vyatarat — granted; bhāgineyāya — to his sister’s son; sutām — his daughter; kurvan — doing; svasuḥ — of his sister; priyam — the pleasing.
Translation: 
Though Rukmī always remembered his enmity toward Lord Kṛṣṇa, who had insulted him, in order to please his sister he sanctioned his daughter’s marriage to his nephew.
Purport: 

The answer to King Parīkṣit’s question is given here. Ultimately Rukmī approved his daughter’s marriage to Pradyumna in order to please his sister, Rukmiṇī.