After He had stolen some curd from the pots of two gopis, Krsna told one of His gopi friends: "My dear beautiful friend, I can take oath that I have not stolen even a drop of curd from your pot! But still, your friend, Radharani, is very shamelessly smelling the flavor of My mouth. Kindly forbid Her from this devious policy of putting Her face near Mine." When Krsna was speaking like this, the friends of Radharani could not check their laughter. This is an instance of ecstasy in conjugal love.
Link to this page: https://prabhupadabooks.com/nod/33/laughter