It's becoming really painful to read both of them together like this. Every encounter ends in shame and misery. I know Remus will torture himself with this the rest of his life, but worse is Teddy. Some day, he will look back at this time and realise how he was about it, and I think he'll cringe. This will become a constant, that thing that bugs you about your life that never goes away....
It feels very Greek Tragedy right now. I know you probably didn't mean it to, and that it will probably be all right in the end, but right now in the story....owie.