CC Madhya 14.157

gopikāra preme nāhi rasābhāsa-doṣa
ataeva kṛṣṇera kare parama santoṣa
Synonyms: 
gopikāra — of the gopīs; preme — in the loving affairs; nāhi — there is not; rasa-ābhāsa — of an adulterated taste of mellow; doṣa — fault; ataeva — therefore; kṛṣṇera — of Lord Kṛṣṇa; kare — they do; parama santoṣa — highest satisfaction.
Translation: 
“There is no flaw or adulteration in the love of the gopīs; therefore they give Kṛṣṇa the highest pleasure.
Purport: 

Rasābhāsa occurs when one’s relationship with Kṛṣṇa is adulterated. There are different types of rasābhāsa — first class, second class and third class. The word rasa means “mellow,” and ābhāsa means “a shadow.” If one tastes one kind of mellow and something extra is imposed, that is uparasa. If something is derived from the original mellow, it is called anurasa. If something is appreciated that is far removed from the original mellow, it is called aparasa. Uparasa, anurasa and aparasa are, respectively, first-, second- and third-class rasābhāsas. As stated in the Bhakti-rasāmṛta-sindhu (4.9.1-2):

pūrvam evānuśiṣṭenavikalā rasa-lakṣaṇā
rasā eva rasābhāsā
rasa-jñair anukīrtitāḥ

syus tridhoparasāś cānu-rasāś cāparasāś ca te
uttamā madhyamāḥ proktāḥ
kaniṣṭhāś cety amī kramāt