Nanda
Polyanna
Youw wife has to consent to it herself for it to happen. If you did, she would encourage and support you and the Lord in the decision.
That sounds good in theory, but from what I've read, it doesn't always pan out in practice. Dorothy Allred Solomon talks about this in her memoir, "Daughter of the Saints." She speaks of several instances where women in plural marriage said they were okay with it, wanted to be okay with it, told themselves they were doing God's will, did their best to conform and supportive of it, all for the sake of their husband and community, but ultimately struggled fiercely with jealousy and bitterness their entire lives.