Lono is a sex god, and his job is to cruise around on a rainbow and sprinkle the world with ... you don't want to know. By arriving not only on a vessel that looked just like Lono, but also on the same day as his annual festival "Lonomania," Cook presumably responded with the loudest "Hey everybody, we're all gonna get laid!" this side of Caddyshack.
Thus the captain, tempted by the perks of being a penis-king, decided to go along with the charade by allowing himself to be smeared with pig fat, and then showing off some fireworks he happened to have in his boat.
Capt. Cook ... the world's first Texan?
Unfortunately for Cook, the Hawaiians were pretty pissed when he paid them a second visit, and not just because of the mounting list of paternity suits awaiting him. Cook's fleet had suffered a heavy battering during a wild storm, and the Hawaiian natives were deeply offended that Cook's ships had returned in such poor condition. Instead of pig fat and flower necklaces, the natives were waiting for him with clubs and daggers.
The instant Capt. Cook realized that his fertility feast-days were over.
Cook tried to explain that it was due to the shitty weather he had recently experienced on his rainbow, but the islanders wouldn't have it. Cook was "clubbed, repeatedly knifed, half-drowned and battered about the head with a rock," at which point we imagine the islanders realized that the man was not a god after all. The fraud was subsequently scarified, torn to pieces, eaten and whatever they didn't finish was made into trophies. The lesson? It is entirely possible to pretend to be a god, but just politely leave after your festival is over. It's not the sort of thing you can keep up forever.
Visit beautiful Hawaii!