At that time (when the cowherd men came down from Govardhana and saw their sons (Krsna's cowherd boy expansions)), all the thoughts of the cowherd men merged in the mellow of paternal love, which was aroused by the sight of their sons - SB 10.13.33

Expressions researched:
"At that time, all the thoughts of the cowherd men merged in the mellow of paternal love, which was aroused by the sight of their sons"

Srimad-Bhagavatam

SB Canto 10.1 to 10.13

At that time, all the thoughts of the cowherd men merged in the mellow of paternal love, which was aroused by the sight of their sons. Experiencing a great attraction, their anger completely disappearing, they lifted their sons, embraced them in their arms and enjoyed the highest pleasure by smelling their sons' heads.

SB 10.13.33, Translation and Purport

At that time, all the thoughts of the cowherd men merged in the mellow of paternal love, which was aroused by the sight of their sons. Experiencing a great attraction, their anger completely disappearing, they lifted their sons, embraced them in their arms and enjoyed the highest pleasure by smelling their sons' heads.

After Brahmā stole the original cowherd boys and calves, Kṛṣṇa expanded Himself to become the boys and calves again. Therefore, because the boys were actually Kṛṣṇa's expansions, the cowherd men were especially attracted to them. At first the cowherd men, who were on top of the hill, were angry, but because of Kṛṣṇa the boys were extremely attractive, and therefore the cowherd men immediately came down from the hill with special affection.