Grandmother gets a different kiss than a husband. We worship God bodily through our posture, our voices, our gestures, and our behavior. We can express ourselves, our love, and give glory to God through our bodies. It is no less than our origin and our calling. We believe God is love.
Love is, first, a choice based on knowledge.
Third, permanence is essential to love. Fourth, love is life-giving. In marriage, love can be expressed in and through the human body through sexual intercourse. All of these aspects of love show that sexuality is a body language properly expressed only in marriage. Outside of marriage, sex is a lie it is missing one or more essential ingredients.