That does not sound like an appropriate assignment at all, and has nothing to do with the subject. I personally, would also refuse to do it and definitely refuse to read it out loud. She has no right to give you an F. I've argued with several teachers about stupid assignments and problems also (like trying to give the entire class an F because they were screwing around/being loud....I didn't deserve an F, I was sitting there, absolutely silent) I commend you for having the courage to talk to the principal.

p.s. If it were me I couldn't do the assignment anyway...lol...I've never been on a date!

p.s.s. Maybe it's an English teacher thing?? I only had one English teacher I actually liked! The rest were nutty! Don't get me started on MY 9th grade english teacher!