"I'd like to see you try," James said, drowsily amused. He purposefully gave a more enthusiastic tousle, and then let it go, arms going back around his best mate.
"It's weird, right?" he agreed. He was quiet for a moment, content to be fully in the moment, and then added, "It's totally weird." It wasn't weird, but it was, at the same time. Whenever he thought too hard about it, it was really fucking strange. And yet, when he was actually hanging out with the two of them, it wasn't so weird. "I mean, I'd adopt little you in a second, so I kind of get that. And you'd adopt little me, yeah?"
But it was slightly different, because none of them grew up to be in love with each other. Not in the same way, anyway. He loved Sirius, but not in the way that would give him a complex if he ended up seeing his best mate as his dad.