Krishna sometimes likes to see his devotees happy. So our being happy is for Krishna’s pleasure. That is the mood of the gopis. The gopis want nothing for themselves but they enjoy more than Krishna, because Krishna is so pleased by their unmotivated service. Willing to go to hell for ever, just to give Krishna a moment of relief from a headache, willing to abandon their children, some of them, their husbands, their mothers, their fathers, their homes, all of their possessions, everything, to run out to the forest to meet Krishna with no thought that they may never be allowed home again, they’ll just be forest dwellers for rest of their lives. They were prepared to do that. Not for their own pleasure, but to satisfy Krishna. And Krishna reciprocates seeing how much they want to please Him by giving them more pleasure than He experiences. Now how is that possible?