Canto 3 -
Araṇya-kāṇḍa
Chapter 38: Mārīca Instructs Rāvaṇa
Text 3.38.24
क्रीडारतिविधिज्ञानां समाजोत्सवशालिनाम्।
रक्षसां चैव सन्तापमनर्थं चाहरिष्यसि॥
krīḍā-rati-vidhijñānāṁ samājotsava-śālinām
rakṣasāṁ caiva santāpam anarthaṁ cāhariṣyasi
krīḍā-rati-vidhijñānām = who know the regulations for sportive enjoyment; samāja-utsava-śālinām = and who are habituated to festivities in assemblies; rakṣasām = to rākṣasas; ca eva = and; santāpam = agony; anartham = distress; ca = and; āhariṣyasi = you will diligently bring about.
And you will diligently bring about distress and agony to rākṣasas who know the regulations for sportive enjoyment and who are habituated to festivities in assemblies.1
1 Rāmāyaṇa-bhūṣaṇa: anarthaṁ duḥkham. santāpaḥ tat-kāryam.
Krīḍā-rati-vidhijñānām indicates that [the rākṣasas in Laṅkā] knew about and were attached to the regulations, that is, the [proper] sequence of engaging in [romantic] play and [conjugal] enjoyment.