SB 10.32.19

bhajato ’pi na vai kecid
 bhajanty abhajataḥ kutaḥ
ātmārāmā hy āpta-kāmā
 akṛta-jñā guru-druhaḥ
Synonyms: 
bhajataḥ — with those who are acting favorably; api — even; na — not; vai — certainly; kecit — some; bhajanti — reciprocate; abhajataḥ — with those who are not acting favorably; kutaḥ — what to speak of; ātma-ārāmāḥ — the self-satisfied; hi — indeed; āpta-kāmāḥ — those who have already attained their material desires; akṛta-jñāḥ — those who are ungrateful; guru-druhaḥ — those who are inimical to superiors.
Translation: 
Then there are those individuals who are spiritually self-satisfied, materially fulfilled or by nature ungrateful or simply envious of superiors. Such persons will not love even those who love them, what to speak of those who are inimical.
Purport: 

Some people, being spiritually self-satisfied, do not reciprocate others’ affection because they want to avoid entanglement in mundane dealings. Other persons do not reciprocate simply out of envy or arrogance. And still others fail to reciprocate because they are materially satisfied and thus uninterested in new material opportunities. Lord Kṛṣṇa patiently explains all these things to the gopīs.