As we know, Peter Pettigrew is now the owner of a silver hand and werewolves can only be killed by a silver bullet. Unfortunately, as we also know, Remus Lupin is a werewolf. Do I believe that Lupin will be killed by Pettigrew? That's hard to say, but as of right now, I will stick to 'no.'
Why I feel as I do about this is because face it, Pettigrew is a coward. He is a rat (no pun
intended) and a coward and a liar, and responsibility is not one of his strong suits. While working for Voldemort might be some kind of an accomplishment for him, he is also on the Dark Lord's last nerve. Another failure would result in imminent death. Why, then, would he not kill Lupin when faced with the courageous werewolf?
Like I said, Pettigrew is a coward, and because he's a coward, he wouldn't kill Lupin. As old Hogwarts friends and a fellow Marauders, Pettigrew and Lupin continue to share a bond inside of them that reminds each of them of the past. Pettigrew killing Lupin would be like you killing your childhood best friend- it just wouldn't happen. Sure, Pettigrew can, as the cliche says, talk the talk, but ultimately, will he be able to walk the walk, when face to face with the man he onced shared all of his Hogwarts experiences, secrets, and feelings with?