Final answer:
Poseidon's true feelings for Percy can be inferred as genuine affection and paternal love, reflecting a complex divine father-son relationship, as evident from Poseidon's emotional and passionate nature depicted in mythology.
Step-by-step explanation:
Based on Percy's and Poseidon's interaction at Mount Olympus, we can infer that Poseidon harbors genuine affection for Percy. Although the specifics of their interaction are not provided, we can look at the broader context of Poseidon's character in mythology. For instance, in the story where Poseidon creates a sea-monster to punish Queen Cassiopeia for her vanity, it shows that Poseidon has a keen sense of justice and acts strongly on his emotions. Thus, it is conceivable that Poseidon, as a character capable of such strong emotional reactions, would have a profound paternal love for Percy.
Additionally, the stories of Greek gods often depict them with human-like emotions and relationships. Hence, it can be inferred that Poseidon's true feelings towards Percy would be a mixture of pride, affection, and perhaps a complex sense of responsibility, reflective of a divine father-son relationship.