Straight Men, about how many of your female friends and aquaintances have you sexually fantasized? Straight Women, about how many of your male friends have you sexually fantasized?

Extra questions: How frequently? With how many would you actually have sex given the opportunity? How much do you guess the average female and average male do this? How many would you want to date or have a romantic relationship with if the opportunity presented itself?

Edit/Note: I've see the main question has been asked to dudes before at reddit and most of them fantasized about most of their friends it seems. But that's reddit.