No one sees sex in this poetic way? Really? Because i do. You are wrong to say that everyone has sex simply for gratification - this is not true. You cannot make blanket statements like that. For this matter i could say everyone eats food simply to fulfill their own selfish desires - no, thats not true. We eat food to heal our bodies, and to share in a meal with our family. Sharing in love is not WRONG and i would be shocked and dismayed to see that any follower of Krsna say "Love is wrong."
I am sad to see you say that living unselfishly is impossible. However, i would disagree. With your arguement, one could say that chanting the mahamantra is "selfish" because we gain something from it. How absurd!