Wrong. God created marriage to be between one man and one woman, not two men, one man and two women or a man and his horse. Biblical adulturey is sleeping with someone of whom you are not married to, engaging in fornication or sodomy.
Evidence? This would seem to go against all those Patriarchs in the bible who have wives and concubines and never seem to be denigrated because of it.
Please provide quotations of the verses that support your statement.
See these for the it is OK side
Genesis 4:19
And Lamech took unto him two wives.
Genesis 16:1-4
Now Sarai Abram's wife bare him no children: and she had an handmaid, an Egyptian, whose name was Hagar. And Sarai said unto Abram, Behold now, the LORD hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her. And Abram hearkened to the voice of Sarai. And Sarai ... gave her to her husband Abram to be his wife. And he went in unto Hagar, and she conceived.
Genesis 25:6
But unto the sons of the concubines, which Abraham had....
Genesis 26:34
Esau ... took to wife Judith the daughter of Beeri the Hittite, and Bashemath the daughter of Elon the Hittite.
Genesis 28:9
Esau .. took ... Mahalath the daughter of Ishmael ... to be his wife.
Genesis 31:17
Then Jacob rose up, and set ... his wives upon camels.
Genesis 32:22
He [Jacob] ... took his two wives, and his two womenservants.
Ex.21:10
If he take him another wife....
Dt.21:15
If a man have two wives, one beloved, and another hated....
Judges 8:30
And Gideon had threescore and ten sons of his body begotten: for he had many wives.
1 Sam.1:1-2
Elkanah ... had two wives; the name of the one was Hannah, and the name of the other Peninnah.
2 Sam.12:7-8
Thus saith the LORD God of Israel ... I gave thee ... thy master's wives....
1 Kg.11:2-3
Solomon ... had seven hundred wives ... and three hundred concubines.
1 Chr.4:5
And Ashur the father of Tekoa had two wives, Helah and Naarah.
2 Chr.11:21
Rehoboam ... took eighteen wives, and threescore concubines.
2 Chr.13:21
But Abijah waxed mighty, and married fourteen wives....
2 Chr.24:3
Jehoiada took for him two wives....
Mt.25:1
Then shall the kingdom of heaven be likened unto ten virgins, which took their lamps, and went forth to meet the bridegroom.
1 Tim.3:2
A bishop then must be blameless, the husband of one wife....
Titus 1:6-7
If any be blameless, the husband of one wife, having faithful children not accused of riot or unruly. For a bishop must be blameless.