Using straight people (the only ones following biological design) a man gives a woman an enormous load. She takes it in, it feels great. BUT is love not something more profound than merely a transfer of fluids? If so what is a valid expression of love?
The only one I can think of is proven over time my commitment and keeping things exclusive in a relationship. Any other ideas?
Foofa
It's the trust she shows him in allowing him to both penetrate her body and leave his genetic materials inside her that is the display of love. But you're correct that people can mimic this without love as its motivation and you're right that only commitment proven over time can be construed as real "love".
The Oracle of Omigod
Love is something more than a transfer of fluids but passionate love is not less than a transfer of fluids.
?
The feeling of love between partners is designed for reproductive purposes. When you have sex kiss someone a series of hormones create the feeling of attachment.
To put in other way sex is just something your programmed to do. But is nice feeling.