WordNet sense 1 (an inability to resist the gratification of whims and desires):

self-indulgence

WordNet sense 2 (a disposition to yield to the wishes of someone):

lenience, leniency

WordNet sense 3 (the act of indulging or gratifying a desire):

humoring, indulging, pampering

WordNet sense 4 (foolish or senseless behavior):

craziness, folly, foolery, lunacy, tomfoolery