Srimad-Bhagavatam: Canto 9 - Chapter 1 - Verse 18

Sanskrit:

पूर्णं वर्षसहस्रं मे विषयान् सेवतोऽसकृत् ।तथापि चानुसवनं तृष्णा तेषूपजायते ॥ १८ ॥

ITRANS:

pūrṇaṁ varṣa-sahasraṁ meviṣayān sevato ’sakṛttathāpi cānusavanaṁtṛṣṇā teṣūpajāyate

Translation:

I have spent a full one thousand years enjoying sense gratification, yet my desire to enjoy such pleasure increases daily.

Purport:

Mahārāja Yayāti is explaining, in terms of his actual experience, how strong are sexual desires, even in old age.