That doesn t sound like love to me. We damage each other. Without exception, your inner being is damaged in every case regardless of how mature you are, how committed you are, or how long you ve been going with each other. There is always damage and God doesn t want us to be hurt. Another reason sex outside of marriage is wrong is because there s a lack of commitment.
Marriage is the legal, publicly witnessed and binding commitment between a man and a woman.
Nothing else is. In marriage, God fuses two into one. So it s not just a physical joining, it s a spiritual joining of two people. In sex outside of marriage there is an intermingling which is ripped into two again. It s the difference between tying branches on the Christmas tree for looks, and the ones that grew there.