since its a controversial issue for those who support evolutionary biology to a greater extent,and they feel its just a matter of gene which they want to transfer to their progeny, and what they called as a selfish gene and also they talk more about sexual selection so to be precise they wanted to relate this as a one of the animal behaviour in a sophisticated manner, but i beleive this is more than that as you mentioned this not about heat period or just to copulate, its about love and many more things which you have already discussed.its good to read and i do agree with you.
