Since the mouth is 'meant' for eating...do you not kiss your beloved?
And the nose was 'meant' for breathing...do you not delight in the fragrance of a favorite flower or a home cooked meal?
Some believe that sex was 'meant' for procreation...ONLY! Do you only engage in love-making in order to procreate? And if so, why are you interested in a Sex and Sexuality forum?!
I am not familiar with the laws of nature to which you refer.