First, Tonberry, if you had read my post carefully you would see that I fully appreciate that there are occasions where people can actually "make love" (as contrasted with "just having sex" -- aka, "casual sex") outside of relationships which explicitly involve future commitment, or commitment to a long-term relationship. I have even indicated that my own life has been nourished by some such experiences (though this was long ago).
Let me get to the heart of the matter of my personal distaste toward "casual sex".
You still reveal yourself naked, just physically rather than emotionally.
Seen open-heartedly, the human being is a whole, an integrity. It is not divided up into categories, but just has its whole life, just as it is. Language and concepts, when they get the upper hand and are not just tools for communication, can wreck havoc on this fundamental human integrity, our wholeness. When we split ourselves into "just physically" on the one side and "emotionally" on the other, and when we make a habit of doing so, we are damaging our capacity to see and live our own wholeness and that of the other. This is why I think all sex should properly be understood and experienced as "love making" -- which is what we call "sex" when we are fully present in it, with ourselves and with our partner/s.
In a better world, we'd live everything as a celebration and nurturance of this integrity, our wholeness and the wholeness of all others. We'd not split ourselves or the others up into tidy little categories which blind us to our own and their own true nature. Whether we are walking, eating, talking, drinking, writing, breathing, thinking ... whatever we're doing, when we bring our whole selves to these actions, the world is loved and healed. As we are, as each being touched by this is.
I don't think we humans should take lightly the fact that we can do things without whole-heartedness. And if we are not fully in touch with our whole-heartedness, we'd do best to practice awakening it in our lives.
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One last thought (on edit):
The physical body simply IS the emotional body. It is simply impossible to touch or be touched without having one's emotional life--and even one's spiritual life--touch and be touched. And every human being rightly should be touched ONLY with love and kindness and open-heartedness. It can truly harm a person to be used as a sex toy or sex object ... while not being
seen as the divine mystery we all ultimately are, in truth.