Percico

Pernico is a half-canon popular ship that originated from the book series "Heroes of Olympus", in the fourth book which is called "House of Hades' by Rick Riordian.

Canon
Percy Jackson and Nico D'Angelo met in the third book of the first Percy Jackson series, called "Titans Curse." Nico and his now deseased sister were attacked by a manticore. We figured out that Nico had liked Percy in the Fourth book of the second series, when Cupid bribes him into revealing his sexual preferences.

Since then, Pernico has been a popular ship that will most likely not come into a reality in the books.

The Real Deal
The Real Deal is that Percy is not gay and has a long time girl -friend, Annabeth. We do not believe that Riordian will kill off Annabeth, a popular character. We do belive that Nico will find someone in the end.

Trivia:
 * Percy is most likely Bisexual, although he has not revealed that yet.
 * The world is round.
 * Yes, I said it.