Your wife would have no such LEGAL authority to make the woman your “wife”;
I understand...Let's compare Gen. 16:3 to Gen. 30:4,9:
3 So after Abram had been living in Canaan ten years, Sarai his wife took her Egyptian slave Hagar and gave her to her husband to be his wife.
Sarai did this. Abram didn't initiate it; nor did God.
Now Genesis 30:
4 So she [Rachel] gave him her servant Bilhah as a wife...9 When Leah saw that she had stopped having children, she took her servant Zilpah and gave her to Jacob as a wife.
So, in Gen. 30, Rachel did the same thing; so did Leah. Jacob didn't initiate it; nor did God.
These were women making decisions based upon...
(a) In Sarai's case, distrust of God [she thought this would be the ONLY way God could fulfill His promise of numerous descendents...given Sarai's age]
(b) In Rachel's case, same motivation:
3 Then she said, Here is Bilhah, my servant. Sleep with her so that she can bear children for me and I too can build a family through her. [Gen. 30:3]
(c) In Leah's case, kinda the same thing...she had "stopped having children" -- so to counter this new barrenness -- and, being in direct competition with the Rachel-Bilhad side -- she copied Rachel's action...
This was all hardly divinely initiated, divinely sanctioned...
LOTS of Scripture describes men and women's sins...doesn't mean the Bible sanctions that activity...just describes it...sometimes even matter-of-factly.