The silence didn't bother Zeus. It was better than getting bitched or yelled at for something he didn't know or remember he'd done - not that it meant anything, his not remembering. Of course, if there had been yelling, Poseidon would still be somewhere on a dusty road and not in this car.
Casting a sideways glance at the sleeping Greek, he picked up the photograph. He wasn't very impressed by what he saw. They used to be the two most powerful gods in the world, striking adoration and fear in the hearts of mortals. They used to stir up storms, cause floods and landslides, filling the realm of Hades with masses of dead, just because they could.
They'd been allies, rivals, and a plethora of other things. On rare occasions, Zeus would remember that they were brothers, too, which, admittedly, was of dubious usefullness given his grasp and understanding of family relations. However, it was apparently good enough to get the Olympian into a car, drive up to Santa Barbara to pick the other Olympian up and then drive around for no reason at all while Poseidon took a nap.
What were they doing?
"Wake up, Sleeping Beauty. It's not much of a romantic 'ride into the sunset' scenario when half of the lovey-dovey couple is snoring away and drooling on himself."