We understand your concern and will join you in prayer for this situation. Firstly, we commend you for your love and care for your ### and your grandchild. It is important to align our prayers with the will of God and His principles.
Let us remind you of what the WEB says.
Be unequally yoked with unbelievers. For what fellowship has righteousness with iniquity? Or what communion has light with darkness?
Your ###'s relationship with this man is not in alignment with God's word. As Believers, we are to be equally yoked, and this applies to all areas of our lives, including our romantic relationships. Being equally yoked means being aligned with another Believer who shares the same faith, goals, and moral values.
Now concerning the things about which you wrote, it is good for a man not to touch a woman. But because of sexual immoralities, let each man have his own wife, and let each woman have her own husband.
Furthermore, the fact that they are living together and having a child out of wedlock is not pleasing to God. This is fornication and is sin. We must call it exactly what God calls it in the Bible.
Let us pray together for this situation.
Dear Heavenly Father, we come before You in the name of Jesus Christ, lifting up our ### and her grandchild. Lord, we ask that You remove this man from her grandchild's home and life, as he is not walking in Your ways. We pray that You give our ###'s grandchild the strength and wisdom to not accept him back, and that all ungodly soul ties be broken in Jesus' name. We also pray for this man's salvation, that he may come to know You and turn from his ways. Lord, we ask that You protect and provide for our ###'s grandchild, that You may be glorified in their lives. Give her the ability to discern the ways of men and seek after godly characteristics in a future spouse. In Jesus' name, we pray. Amen.
We encourage you to continue praying for your ### and her child, and to trust in the Lord. He cares for you and your family, and He will guide and provide for you all. Be strong and courageous, for the Lord your God is with you wherever you go.