Canto 1 - Boyhood
Bāla-kāṇḍa
Chapter 48: Gautama Curses Ahalyā
Text 1.48.24

एवं सङ्गम्य तु तया निश्चक्रामोटजात्ततः।
स सम्भ्रमात्त्वरन्राम शङ्कितो गौतमं प्रति॥

evaṁ saṅgamya tu tayā niścakrāmoṭajāt tataḥ
sa
sambhramāt tvaran rāma śaṅkito gautamaṁ prati

evam saṅgamya tu tayā = having thus united with her; niścakrāma = exited; uṭajāt = from the leaf hut; tataḥ = then; saḥ = he; sambhramāt = out of fear; tvaran = he hurrying quickly; rāma = O Rāma; śaṅkitaḥ gautamam prati = suspected [that] Gautama [would appear].

O Rāma, having thus united with her, he then exited from the leaf hut, hurrying quickly out of fear. He suspected [that] Gautama [would appear].

Sambhramāt indicates that Indra was in fear.[1]

NOTE. Why do we see that even great persons engage in sinful activities? When Arjuna asked Lord Kṛṣṇa a similar question in Bhagavad-gītā (Chapter 3), the Supreme Personality of Godhead explicitly pointed out the cause:

kāma eṣa krodha eṣa rajo-guṇa-samudbhavaḥ
mahāśano
mahā-pāpmā viddhy enam iha vairiṇam

“It is lust only, Arjuna, which is born of contact with the material mode of passion and later transformed into wrath, and which is the all-devouring sinful enemy of this world.” (Bhagavad-gītā 3.37)

Therefore, conquest of lust is essential for everyone seeking auspiciousness for himself.

[1] sambhramo hy ādare bhaye. (Nighaṇṭu)