is not.

Genesis 20:3
One night, however, God came to Abimelech in a dream and told him, "You are as good as dead because of the woman you have taken, for she is a married woman."

Genesis 34:2, 7, 8, 31
When Shechem son of Hamor the Hivite, the prince of the region, saw her, he took her and lay with her by force. . . .

Numbers 5:29
This is the law of jealousy when a wife goes astray and defiles herself while under her husband's authority,

Ruth 4:10
Moreover, I have acquired Ruth the Moabitess, Mahlon's widow, as my wife, to raise up the name of the deceased through his inheritance, so that his name will not disappear from among his brothers or from the gate of his home. You are witnesses today."

Jeremiah 3:20
But as a woman may betray her husband, so you have betrayed Me, O house of Israel, " declares the LORD.

Ezekiel 16:32
You adulterous wife! You receive strangers instead of your own husband!

Mark 10:12
And if a woman divorces her husband and marries another man, she commits adultery."

Romans 7:3
So then, if she is joined to another man while her husband is still alive, she is called an adulteress; but if her husband dies, she is free from that law and is not an adulteress, even if she marries another man.

1 Corinthians 7:10, 11
To the married I give this command (not I, but the Lord): A wife must not separate from her husband. . . .

Hebrews 13:4
Marriage should be honored by all and the marriage bed kept undefiled, for God will judge the sexually immoral and adulterers.