In the main comic storylines, Aquaman is not gay. However, there might be alternate universes or special editions where his character could be portrayed differently, but that's not the norm.
The story of Aquaman involves his struggle to find his place in two different worlds. He faces challenges from both human and Atlantean enemies as he strives to unite the two and bring peace. His powers and connection to the ocean play a crucial role in his adventures.
One possible reason could be that Percy Jackson has some sort of power or achievement that makes Aquaman show respect. Maybe Percy has saved the underwater world in some way, or he has a connection to a powerful underwater deity that Aquaman respects.