Proverbs 6:32-33:

But whoso committeth adultery with a woman lacketh understanding: he that doeth it destroyeth his own soul.
A wound and dishonour shall he get; and his reproach shall not be wiped away.

See also:

Why Does God Keep Using a Certain Healing Minister So Mightily When His Personal Life Is So Messed Up?
Condition: Venereal Diseases