It had to be done. Stiles was dying. So Derek was forced to do the one thing he dreaded the most. Biting the one he loved. The possibility of him dying was 60 40. The thing with Paige made him never want to bite his lover. But he had to do it or he was going to lose Stiles anyway. So he took that chance. The suspense of wondering whether he was going to change or die was killing him and he didn't want anyone near Stiles. So he stood guard and didn't leave his side. Not once