Exodus 20:14 Thou shalt not commit adultery.
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.
Matthew 5:27-
28 Ye have heard that it was said by them of old time, 
Thou shalt not commit adultery: ... But 
I say unto you, 
That whosoever looketh on a woman to lust after her 
hath committed adultery with her already in his heart.
Luke 18:20 Thou 
knowest the commandments, 
Do not commit adultery, Do not kill, Do not steal, Do not bear false witness, Honour thy father and thy mother.
James 2:10-
11 For whosoever shall keep the whole law, and yet offend in one [
point], he is guilty of all. ... For he that said, Do not commit adultery, said also, Do not kill. 
Now if thou commit no adultery, yet if thou kill, thou art become a transgressor of the law.