pūrṇaṁ varṣa-sahasraṁ me
viṣayān sevato 'sakṛt
tathāpi cānusavanaṁ
tṛṣṇā teṣūpajāyate
pūrṇam - completely; varṣa-sahasram - one thousand years; me - my; viṣayān - sense gratification; sevataḥ - enjoying; asakṛt - without cessation, continuously; tathā api - still; ca - indeed; anusavanam - more and more; tṛṣṇā - lusty desires; teṣu - in sense gratification; upajāyate - are increased.
Mahārāja Yayāti is explaining, in terms of his actual experience, how strong are sexual desires, even in old age.