no
Actually there won't be a sixth Percy Jackson book cuz Rick Riordan is making a whole new book series about half-bloods with some of Percy Jackson's friends and maybe Percy himself.
Brave
There's not going to be anymore 'Percy Jackson and the Olypians' books but there's going to be another Camp Half-Blood series but to answer your Q, probably, but not the main characters.
From books 1-4 Percy doesn't have a girlfriend even though there is slight flirting with Rachel and Annabeth. By the end of the fifth book Annabeth becomes Percy's girlfriend.
she gets kidnapped
You read book five and you will find out.
In the very last book, him and Annabeth do decide to go out.
Percy Jackson, Annabeth, and Grover
Percy Jackson first kisses Annabeth in the fouth book, Percy Jackson and the Labyrinth, during their escape from a bunch of Telkhines. In the end of the fifth book, Percy Jackson and the Last Olympian, Percy and Annabeth kissed in the hill, after their celebration dinner. Then, the campers, whom all was eavesdropping, lifted them on their soldiers and dumped them into the lake, where Percy then creates an air bubble and had a "underwater kiss of all time".
I think she did because Annabeth Chase is really fast.
the Percy Jackson books
I wonder........ partially luke, partially percy, and "gods" know what other men. (" " are for a pun