Thanks for your replies everyone!
So, one thing I did say as he was trying to shut down the conversation was :
"Dad, we have always been told that whenever we read the bible, we should ask ourselves 'what does this section teach me about Jehovah's personality?' isn't that right?"
His reply was "Well Jehovah could have omitted parts of the bible out if he wanted, but he didn't. Plus, Lot was not even aware that his daughters did that to him!"
I replied with the following: "What, Lot was the VICTIM? A 100 year old man manages to sustain an erection after drinking wine, doesn't know he is even having sex, and his virgin daughters manage to both conceive on their very first attempt at sex, and obviously they were both ovulating at the same time?? Sorry Dad, but I have trouble with this account for so many reasons"