The heart of Lord Caitanya is the image of Śrī Rādhikā’s emotions. Thus feelings of pleasure and pain arise constantly therein.
Lord Caitanya's heart was full of the feelings of Śrīmatī Rādhārāṇī, and His appearance resembled Hers. Svarūpa Dāmodara has explained His attitude as rādhā-bhāva-mūrti, the attitude ofRādhārāṇī. One who engages in sense gratification on the material platform can hardly understand rādhā-bhāva, but one who is freed from the demands of sense gratification can understand it. Rādhā-bhāva must be understood from the Gosvāmīs, those who are actually controllers of the senses. From such authorized sources it is to be known that the attitude of Śrīmatī Rādhārāṇī is the highest perfection of conjugal love, which is the highest of the five transcendental mellows, and it is the complete perfection of love of Kṛṣṇa.
(Sri caitanya Caritamrta----1:4:106----purport).

"The love of Rādhikā is My teacher, and I am Her dancing pupil. Her prema makes Me dance various novel dances."
(Sri caitanya Caritamrta----1:4:124----translation).

"In the forest on the bank of Rādhā-kuṇḍa."
"What is He doing there?"
"He is learning dancing."
"Who is His master?"
"Your image, Rādhā, revealing itself in every tree and creeper in every direction, is roaming like a skillful dancer, making Him dance behind."
(Sri caitanya Caritamrta----1:4:125----translation).

Whatever pleasure I get from tasting My love for Śrīmatī Rādhārāṇī, She tastes ten million times more than Me by Her love.
(Sri caitanya Caritamrta----1:4:126----translation).

Just as I am the abode of all mutually contradictory characteristics, so Rādhā’s love is always full of similar contradictions.
(Sri caitanya Caritamrta----1:4:127----translation).

Rādhā’s love is all-pervading, leaving no room for expansion. But still it is expanding constantly.
(Sri caitanya Caritamrta----1:4:128----translation).

“All glories to Rādhā’s love for Kṛṣṇa, the enemy of the demon Mura! Although it is all-pervading, it tends to increase at every moment. Although it is important, it is devoid of pride. And although it is pure, it is always beset with duplicity.”
(Sri caitanya Caritamrta----1:4:131----translation).

Śrī Rādhikā is the highest abode of that love, and I am its only object.
(Sri caitanya Caritamrta----1:4:132----translation).

I taste the bliss to which the object of love is entitled. But the pleasure of Rādhā, the abode of that love, is ten million times greater.
(Sri caitanya Caritamrta----1:4:133----translation).

Viṣaya and āśraya are two very significant words relating to the reciprocation between Kṛṣṇa and His devotee. The devotee is called the āśraya, and his beloved, Kṛṣṇa, is the viṣaya. Different ingredients are involved in the exchange of love between the āśraya and viṣaya, which are known as vibhāva, anubhāva, sāttvika and vyabhicārī. Vibhāva is divided into the two categories ālambana and uddīpana. Ālambana may be further divided into āśraya and viṣaya. In the loving affairs of Rādhā and Kṛṣṇa, Rādhārāṇī is the āśraya feature and Kṛṣṇa the viṣaya. The transcendental consciousness of the Lord tells Him, "I am Kṛṣṇa, and I experience pleasure as the viṣaya. The pleasure enjoyed by Rādhārāṇī, the āśraya, is many times greater than the pleasure I feel." Therefore, to feel the pleasure of the āśraya category, Lord Kṛṣṇa appeared as Śrī Caitanya Mahāprabhu.
(Sri caitanya Caritamrta----1:4:135----purport).

Only Rādhikā, by the strength of Her love, tastes all the nectar of My sweetness.
(Sri caitanya Caritamrta----1:4:139----translation).

Although Rādhā’s love is pure like a mirror, its purity increases at every moment.
(Sri caitanya Caritamrta----1:4:140----translation).

There is constant competition between My sweetness and the mirror of Rādhā’s love. They both go on increasing, but neither knows defeat.
(Sri caitanya Caritamrta----1:4:142----translation).

"If I deliberate on a way to taste it, I find that I hanker for the position of Rādhikā."
Kṛṣṇa's attractiveness is wonderful and unlimited. No one can know the end of it. Śrīmatī Rādhārāṇī alone can relish such extensiveness from Her position in the āśraya category. The mirror of Śrīmatī Rādhārāṇī’s transcendental love is perfectly clear, yet it appears clearer and clearest in the transcendental method of understanding Kṛṣṇa. In the mirror of Rādhārāṇī’s heart, the transcendental features of Kṛṣṇa appear increasingly new and fresh. In other words, the attraction of Kṛṣṇa increases in proportion to the understanding of Śrīmatī Rādhārāṇī. Each tries to supersede the other. Neither wants to be defeated in increasing the intensity of love. Desiring to understand Rādhārāṇī’s attitude of increasing love, Lord Kṛṣṇa appeared as Śrī Caitanya Mahāprabhu.
(Sri caitanya Caritamrta----1:4:145----translation and purport).