We understand your urgency and desperation, but we need to address a few things before we pray together for you and your husband. First, we want to remind you that God hears our prayers even when we are distressed. The Bible tells us in James 5:16, Be confessing therefore your sins to one another, and praying for one another, that you may be healed. The insistent prayer of a righteous person is powerfully effective. We must trust in God's timing and remember that God is working things together for good for those who love Him and are called according to His purpose. - Romans 8:28.
First, we notice that you have not mentioned anything about forgiveness, but instead focus on the removal of this person from your husband's life. While asking God to intervene is appropriate, we must remember Jesus' teaching on this. In Matthew 18:21-22. Then Peter said to Jesus, Lord, how often shall my brother sin against me, and I forgive him? Until seven times? Jesus said to him, I don't tell you until seven times, but, until seventy times seven.
We are instructed in Ephesians 4:31-32. Let all bitterness, wrath, anger, outcry, and slander, be put away from you, with all malice. And be kind to one another, tenderhearted, forgiving one another, even as God for Christ's sake hath forgiven you.
We notice that this prayer request does not mention anything about restoration and forgiveness.
We also need to remind you that God will not force anyone to do anything against their will. This includes your husband's feelings and actions. We can pray for God to soften his heart and draw your husband closer to Him and that he would be faithful and loving towards you, but ultimately, your husband has free will and his actions and decisions are his responsibility. We can pray for the conviction of the Holy Spirit to guide your husband's thoughts, desires, and actions.
Finally, we must address that your prayers are not the only ones God hears. The other woman is also someone for whom Jesus died. We must pray for her as well, that God would work in her life. We should pray for her salvation and that God would help her to do what is right and honorable in His sight.
Let us pray together for you and your husband, remembering that God's will for you is to have happiness and holiness in your marriage. We must pray in faith and trust in God's timing and will.
Heavenly Father,
We come before You, lifting up our sister in Christ and her husband. We ask, Lord, that You would intervene in their marriage, that You would soften her husband's heart and draw him closer to You. We pray that You would help him to be the husband that You have called him to be, loving and faithful to his wife. We ask for forgiveness on his behalf if needed and we ask that you would help him to forgive any who have wronged him.
Lord, we also lift up this other woman to You. We pray for her salvation if she is not already saved and for a revelation of Your love and mercy towards her. We ask that You would work in her life and help her to do what is right and honorable in Your sight.
Father, we ask for healing and restoration in this marriage. We pray for Your will to be done and for You to bring joy and happiness to this couple. We ask for forgiveness where it is needed and for love to abound. We ask for wisdom and guidance for both of them, that they would seek Your face and trust in Your timing.
Lord, help us all.
In Jesus' name we pray. Amen.
This may not have been the prayer you were hoping for, but we have faith that this prayer and the truth of God's word will bring the desired results as you and your husband come closer to God, and He draws closer to you.
Prayer Focus: God, Thank You for loving me. God, I ask You in Jesus’ name please bless me with everything that I stand in need of and everything You want me to have. 
