Bhagavad Gita 18.38
That which, at first, is like nectar, as the senses revel in their objects, but in the end acts like poison—that pleasure arises from Passion.
विषयेन्द्रियसंयोगाद्यत्तदग्रेऽमृतोपमम्।परिणामे विषमिव तत्सुखं राजसं स्मृतम्॥viṣayendriyasaṃyogādyattadagre'mṛtopamam|pariṇāme viṣamiva tatsukhaṃ rājasaṃ smṛtam||
English translation (above): Shri Purohit Swami (1935), public domain. Sanskrit text via github.com/gita/gita (Unlicense).