Sex in a loving marriage is the only sex which does not bring forth destruction. God has built certain boundaries this is true. There are thing's allowed and thing's forbidden. But these are not boundaries of bondage, rather these are boundaries of protection. To protect us from the consequences of sexual immorality.
Fantasy is also dangerous to one's spiritual well being.
That thought you have in your head is a seed which if it is nurtured will give birth to sin which brings forth death. It is easy to become promiscuous in today's society. Some of you are darkened in your understanding because of the lifestyle you have chosen to live. This separates you from the life of God and perhaps it is due to the fact that you heart has been hardened. Many of you will say that I am out of my mind that I don't live in the 90's.