If the guy only killed one parent- say, the dad, then I could
see how she might think it was okay to go off with her boyfriend and marry him. But, he killed both of them which is really over the top. She probably should have said she would continue dating him but not marry him. She should have known better.
One is OK, but 2 is too much?
I don't get your reasoning.
I don't think many on this thread are going to get your sense of humor.