lol ya in Heroes of Olympus book #2, Son of Neptune, you learn it some sense Hera threw percy into the same situation but of course he still had his curse so he went super fast through it all.

we have no idea what happens at end of HOO so there is no guarantee they made friends or anything permanently, they could of limited time teamed up then went home and stay at separate camps, because it is harder for them to control themselves around each other... after all it was incredibly easy to get Percy and Jason to fight each other, luckily stopped before one got killed. 

I haven't reached end of book #5 of HOO, so far it doesn't seem like this is the final book, there is probably going to be one or two more after this knowing Rick Riordan sense this is his best works after all, got to make it last lol. personally I hate it that he made the Kane Chronicles so short... that series could of been made longer but instead it is only 3 books.