The account does not prohibit sex. More has to be 'read into it' in order for the reader to come away with that idea. The account does tell us that a change came over the man and the woman even before God spoke to them. They became ashamed of their nakedness. An innocence was lost with the partaking of the fruit, a relationship died that day. Some theologians say that the death of which God spoke was the spiritual death of Adam and Eve. God did not lie. The serpent was not entirely untruthful either, but then how many liars do you know use the truth to mask their falsehoods? They all do. The serpent said that she would not die. She died, figuratively, spiritually, and eventually literally. Why was that fact not brought out in the discussion yet? Why is only God accused of lying?
The Bible does more than relate past events. It serves to help us see ourselves, our motives, our hearts. It appears that we can only see what we allow ourselves to see. Some see good there, others see only evil. Adam and Eve were allowed to see in a way never before allowed them. They became like God in their ability to see evil and good and what was the result of that marvelous insight? What did they see when their eyes were opened and the viewed paradise and looked upon themselves, the crowning achievement of God's creative work? The saw something about their bodies that made the ashamed. Of all the wonderful things to see, they saw something ugly in something that was beautiful...Sort of like when we look into the Bible. What do we see???