Undertale - Me, Papyrus, sans and god knows how many random monsters had brothers

You know, if sans wasn't such a fucking lazy idiot and killed me when I was still weak, let's say as soon as I exited the ruins ( or at least after Snowdin evacuated, when he know for sure that I am killing everyone), he could have saved his brother and everyone else. But no, he had to wait until everyone was dead to fight me. sans is as guilty of their deaths as I am. Papyrus died because of him.
What a pathetic excuse of a brother.