I don't want my girlfriend to google who dies in the walking dead as we watch it together
Do you think your girlfriend will look up who dies in the walking dead and spoil it for you?
Yes, and she'll probably come up with some kinda stupid reason for it
That's rude of her and it spoils the show. It's not good to want to wreck a show for others.
She argues that it's not wrecking to make predictions.
Well you should tell her to keep her predictions to herself. What she's doing is very rude to you.