OC1 is headed to a tropical getaway, but disaster strikes on the plane ride there. One of the engines fail, sending the airplane hurling into the ocean!
OC1 narrowly survives, waking up on a small, deserted island. Luckily, there's a small village living on the island, and the villagers agree to take OC1 into the village and help them out. They shower their guest in food, providing all the delicious, island delicacies that OC1 could possibly eat.
After a while, this royal treatment begins to take its affect on OC1's figure, with them growing larger and larger by the day. Soon enough, they've grown absolutely massive, but the villagers don't seem to show any signs of stopping. Will OC1 find their way back to civilization? Or will they eat themselves into immobility at the hands of the villagers?
For this plot, OC2 can either be a fellow passenger on the plane, who is treated to the same gluttonous luxury as OC1, or one of the villagers, who's in charge of caring for OC1 as they're fattened up.
The villagers' motives are also up to you to decide: Maybe they mistake OC1 for some kind of god or spirit, and are feeding them as a form of worship. Or perhaps they have a more nefarious purpose, that won't become to apparent to OC1 until they're fat enough for whatever the villagers have planned...