SB 9.18.3

pitari bhraṁśite sthānād
 indrāṇyā dharṣaṇād dvijaiḥ
prāpite ’jagaratvaṁ vai
 yayātir abhavan nṛpaḥ
Synonyms: 
pitari — when his father; bhraṁśite — was caused to fall down; sthānāt — from the heavenly planets; indrāṇyāḥ — of Śacī, the wife of Indra; dharṣaṇāt — from offending; dvijaiḥ — by them (upon her lodging a complaint with the brāhmaṇas); prāpite — being degraded to; ajagaratvam — the life of a snake; vai — indeed; yayātiḥ — the son named Yayāti; abhavat — became; nṛpaḥ — the king.
Translation: 
Because Nahuṣa, the father of Yayāti, molested Indra’s wife, Śacī, who then complained to Agastya and other brāhmaṇas, these saintly brāhmaṇas cursed Nahuṣa to fall from the heavenly planets and be degraded to the status of a python. Consequently, Yayāti became the king.