I get it's for the advancement of the plot, but this logic is just stupid. Why'd he bring her home if he was so afraid of her? BECAUSE SHE CRIED? Wtf logic is that? She just killed a guy with a needle that was poking out of her arm! You foresaw that she's some kind of non-human creature. She's clearly beyond dangerous and he still bring her home because...well she cried. Remind me to just cry when I hold a person hostage. Really get that Stockholm syndrome to trigger real quick.