I believe the bare essential needs are subsistence and survival. Other basic needs we have are for affection, belonging and understanding. Sex and feeling close and connected to someone is part of our basic human needs. How we meet those needs have changed through history and the different cultures and areas of the world.
Humans have evolved a long way from acting on our base instincts. As societies and culture developed we accepted that we needed to act in a responsible manner with other beings. Villages we formed and people began to act together for the good of the group. Then laws and rules were made to keep peace. And from these rules leaders and enforcers emerged.
Just look at how complicated and busy life has become. We now have TVs and other media outlets telling us what we should want; how we should look; how we should act; how we aren't good enough or important unless we use their product or believe as they do.
This is one of the many reasons I identify with being a Pagan. I don't need to follow someone telling me what is right and wrong. I can figure that out for myself.
Sex is natural. Wanting to connect to others and feel love is a basic need. I respect others and I act as responsibly as I can. I try to live in this moment and there is noting wrong with fulfilling one of our basic needs. I don't think I'm being sleazy at all and who am I to try to tell someone else that their behavior is?