God's word has good insight on that question, the scriptures state very plainly in 1 Thessalonians 4:3-8 - "For this is the will of God, that you should be holy and abstain from sexual immorality. Each one of you should know how to control his own body...not with greedy, uncontrolled sexual passion..because Jehovah (God) exacts punishment for all these things...So, then, the man who disregards this is disregarding not man, but God.." The standard set for sexual relations were not made by men but by our Creator and it is for our benefit. It helps us to avoid the many headaches that come out of practicing sexual immorality. For example unwanted pregnancies, sexually transmitted diseases, trust issues in a relationship, and broken families just to name a few. The most important thing it helps us to avoid is God's disapproval. There fore if we are practicing sexual immorality it would be wise to stop.
Would you like to learn more about this or other topics of interest like when will suffering ever end? Visit www.jw.org