SB 6.14.42

evaṁ sandahyamānānāṁ
 sapatnyāḥ putra-sampadā
rājño ’sammata-vṛttīnāṁ
 vidveṣo balavān abhūt
Word for word: 
evam — thus; sandahyamānānām — of the queens, who were constantly burning in lamentation; sapatnyāḥ — of the co-wife Kṛtadyuti; putra-sampadā — due to the opulence of a son; rājñaḥ — by the King; asammata-vṛttīnām — not being very much favored; vidveṣaḥ — envy; balavān — very strong; abhūt — became.
Translation: 
Śrī Śukadeva Gosvāmī continued: Being neglected by their husband and seeing Kṛtadyuti’s opulence in possessing a son, Kṛtadyuti’s co-wives always burned in envy, which became extremely strong.