The premise has been posed that physical acts are never sinful, only the sinful disposition of the mind is sin. Try this out. I have no disposition of the mind to commit adultery. I am not lusting at another woman. However, I do have physical sexual urges that I need satisfied. Therefore, I choose to alleviate or satisfy these desires by having sex with a woman not my wife. But its not adultery, because I am not lusting after her nor do I desire her emotionally or spiritually. I just need to satisfy a physical need which is normal and healthy with a physical act of intercourse. No sinful dispostion of the mind. Therefore, no sinful act! Now isn't that right! We even hear those who think like this say, "It didn't mean anything! It was just sex."