The first vore scene occurred in one of the rooms where some strange artifact took control of Trico's mind for a bit and you played for a bit avoid him until he grabs you and gobble you up. After which a flashback occurred which is some of Trico's memories and such. After which the boy wakes up to find Trico unconscious and that he lost his shield that allowed Trico to produce lightning from its tail.
The second vore scene occurred in the room similar to the one from before. Another strange artifact that looked exactly the same as the first one took control of Trico's mind again and as before the creature ate the boy again. Again a flashback occur only this time its more clear and from a third person view. And the flashback shows exactly how the boy was taken to "the nest". After the flashback Trico regurgitated the boy and tried to wake him up.
The third vore scene occured in the flashback mentioned above. In the flashback Trico under the influence of the final boss, came to the village at night and peeks his head into the home where the boy lives. The boy was having a nightmare, and after the creature inspected the boy, he ate him so that he can take him back to "the nest" but he was attacked by the villagers as he makes his getaway. As Trico flies near "the nest", he was struck by lightning and fell into "the nest" unconscious. Then he was taken to where he was chained up in the first place. Afterwards, Trico unconsciously regurgitated the boy who now bears markings all over his body.
The fourth and final vore scene occurred after you defeat the final boss. Trico successfully carried the boy to the outer edge of "the nest" and tried to wake him up. But when it realize that the boy is too weak, he ate the boy again and send him into his crop so that he can take the boy back to his village from where he was kidnapped. And when he arrived by crash landing, he regurgitated the boy in front of the villagers.
There's another scene before the final boss fight, that is somewhat vore related. It shows the reason why Trico kidnapped the boy in the first place, while being influenced by the final boss. The other tricos land on top of the tower and regurgitated the humans into a strange statue, then a rumble occurred and a barrel pops out. The same type of barrels that Trico eats. So now we know what Trico was eating in those barrels.
EDIT: The last one was out of order I know. But I didn't exactly count it as vore since it didn't show any eating. It showed regurgitation though, but I see it more as reverse vore.
