James ignored Lily's advice, as he usually did when someone tried to tell him his idea of teasing didn't always go over well with others.
He wondered where Harry worked, but there would be time for that. Time for all those questions and discussions. Right now, he really just wanted to be on his own to think about what he'd already learned rather than just react. Reacting was well and good until it became all one did.
He did see Lily fiddling with her necklace, and he smiled when he saw it, eyes threatening to tear again. But he managed to stop them, and looked back to Harry. His son. Harry. Who was his son. Giddiness fluttered in his stomach at the idea of being called "dad," but for the moment his head won out, and he put a hand on each of Harry's shoulders.
"I think... it's not really up to me. If you want to call me Dad, you can. It's not that I don't want you to, but this is a lot. For both of us. And it's happening very fast. I don't want you to start something you may wish you hadn't later."
Merlin, it killed me to say that. But... that's part of why he needed to leave. There were more things going on here than just a father and son reunion. There was Lily to think about, and what he wanted to do--that part wasn't in question, really--and how he wanted to go about them. Like explaining it all to his boss and co-workers. Should he? How? What to tell them and what not to tell them. Whether he liked to think about it or not, and he didn't, this could be dangerous for all of them, and not just from pureblood co-workers who would just not care for the idea of him dating or marrying or having had a child with a Muggleborn. There were other considerations.