CC Adi-lila 17.293 - Ujjvala-nilamani
Sri Caitanya-caritamrta
CC Adi-lila
CC Adi 17.293, Translation and Purport:
"Prior to the rāsa dance, Lord Kṛṣṇa hid Himself in a grove just to have fun. When the gopīs came, their eyes resembling those of deer, by His sharp intelligence He exhibited His beautiful four-armed form to hide Himself. But when Śrīmatī Rādhārāṇī came there, Kṛṣṇa could not maintain His four arms in Her presence. This is the wonderful glory of Her love."
This is a quotation from the Ujjvala-nīlamaṇi (Nāyikā-bheda 7), by Śrīla Rūpa Gosvāmī.