Remus's shoulders sagged as he listened to his son speak. Teddy wanted what any other boy his age, or younger, or older, wanted; a family. He'd never had one, not his real one, because they'd died. Because Remus had died. He'd help bring this child into the world and didn't stick around to see it through. He wasn't a father. He had fathered Teddy, but he wasn't a dad. And who could fault Teddy for wanting this, for expecting it? Remus himself had, until just recently, expected to get to keep the family he'd made for himself back home. Or that he would make.
"Teddy," he started, and then sighed. It was such a pity. "It's not Sirius's fault," Remus explained. Though he knew it would probably be best for everyone if he left the blame on Sirius, he couldn't bring himself to do it. The blame didn't lie on Sirius and it was unfair to him to allow his son to continue believing that he was at fault here, no matter how much easier it might have made the situation for everyone. "Your mother and I..." He shook his head. "We can't be what the other wants. What the other needs. We love each other back home, I'm sure of it, but people change. I know how that sounds, truly I do. But back home, we have the opportunity to change together, to become right for each other. To come to be the people who are your parents. I don't have that opportunity here. Your mother changed without me, expects me to have changed along with her... but I can't. I can't, Teddy, I hope you can understand that. I can't be who she needs me to be, just like she can't be who I need. She can't turn back time, make herself into the woman I could fall in love with. She's far too... different, now, than when she was when we first started out. I'm sorry, Teddy. I'm so sorry." The words were heartfelt. He truly didn't want to hurt his son. He wanted to love his son, he wanted Teddy to love him. "I'm still your father, Teddy. And I'll be there for you. And so will she. But we're not... strictly speaking together. But we still both love you. Nothing could ever change that."