I think you all are judging both Harry and Lupin to hard.

Lupin - Wanting to go with Harry was it more for wanting to protect the one person he and his three best friends loved or wanting to leave this family.
- REGRETTED MARRYING TONKS because he did not love her or because he loved her too much. Him think what kind of life can she have with him and would she be better off without him.

Harry being to hard on Lupin. Could it because Harry knew it was the only way for Lupin to put this family first? And by asking Harry to be Teddy's godfather his was of thanking Harry for being so hard???