Henry was 'just a kid', huh? Apollo looked over to Hermes at this revelation, at first suspecting that he'd hidden Henry's identity on purpose as some kind of power play, but there was nothing on Hermes' face that suggested that. He simply looked like he was reveling in the knowledge of Lucifer on the other side of the country (but California? Ugh, Apollo loved California, couldn't he go somewhere Apollo was never gonna go? Montana or some shit?)
But, well fuck. Santa Claus had a mortal son. That explained why Henry knew all about them, then. "Badass Santa," Apollo said, impressed with that too (and only momentarily entertaining the motion of pitting Santa against Ares, just as a... thought experiment, of course.)