As a hunter, I can explain this.
Deer cannot see color and actually have incredibly shit eyesight in comparison to something like a turkey or a coyote. They rely mostly on scent and hearing to decide what to do.
They freeze because the light completely blinds them, the car has no natural smell, and all they hear is the same roaring they’ve been hearing the past hour getting slightly louder.
Like a frog in a boiling pot situation, it’s fine until it’s suddenly not and then they can’t see-
I would say yes, then have a talk about safe sex.
Because if you say no? They’ll sneak off somewhere and do it anyway, in a much less safe manner, abd then you just have to hope to NOT hear about it because if you do it’ll be a “I majorly fucked up” one.
So yes. Say yes. Speaking as; somebody’s girlfriend.