SB 10.21.4

tad varṇayitum ārabdhāḥ
 smarantyaḥ kṛṣṇa-ceṣṭitam
nāśakan smara-vegena
 vikṣipta-manaso nṛpa
Synonyms: 
tat — that; varṇayitum — to describe; ārabdhāḥ — beginning; smarantyaḥ — remembering; kṛṣṇa-ceṣṭitam — the activities of Kṛṣṇa; na aśakan — they were incapable; smara-vegena — by the force of Cupid; vikṣipta — agitated; manasaḥ — whose minds; nṛpa — O King Parīkṣit.
Translation: 
The cowherd girls began to speak about Kṛṣṇa, but when they remembered His activities, O King, the power of Cupid disturbed their minds, and thus they could not speak.