One verse

Srimad Bhagavatam 11.3.18

11.3.18

श्रीप्रबुद्ध उवाच कर्माण्यारभमाणानां दु:खहत्यै सुखाय च । पश्येत् पाकविपर्यासं मिथुनीचारिणां नृणाम् ॥ १८ ॥

śrī-prabuddha uvāca karmāṇy ārabhamāṇānāṁ duḥkha-hatyai sukhāya ca paśyet pāka-viparyāsaṁ mithunī-cāriṇāṁ nṛṇām

śrī-prabuddhaḥ uvāca
Śrī Prabuddha said
karmāṇi
fruitive activities
ārabhamāṇānām
making endeavors in
duḥkha-hatyai
for the elimination of distress
sukhāya ca
and for gaining happiness
paśyet
one should see
pāka
of the result
viparyāsam
contrary outcome
mithunī-cāriṇām
who are coupled as men and women
nṛṇām
of such persons

Śrī Prabuddha said: Accepting the roles of male and female in human society, the conditioned souls unite in sexual relationships. Thus they constantly make material endeavors to eliminate their unhappiness and unlimitedly increase their pleasure. But one should see that they inevitably achieve exactly the opposite result. In other words, their happiness inevitably vanishes, and as they grow older their material discomfort increases.