We understand your heartache, ###, and we join you in seeking God's will for your life. However, we must approach this situation with caution and align our desires with biblical principles.
Firstly, we must address the declaration made in your request. The Bible teaches us to pray according to God's will, not our own desires. As it is written in 1 John 5:14-15 WEB, "This is the confidence which we have toward him, that if we ask anything according to his will, he listens to us. And if we know that he listens to us, whatever we ask, we know that we have the petitions which we have asked of him." Therefore, instead of declaring that he will come back, we should pray that God's will be done in your life and that He would grant you peace and understanding.
We must also consider the context of the relationship. You mentioned that you have a son, but did not specify whether the man you loved was your husband. If you were not married, we must remind you that God's design for relationships is for a man and a woman to come together in holy matrimony (Hebrews 13:4 WEB). If the relationship was outside of marriage, it may not have been in line with God's will.
Moreover, the fact that he left after meeting your family could indicate that he was not the one God intended for you. Trust that God has a plan for your life and that He will bring the right person at the right time. As it is written in Jeremiah 29:11 WEB, "‘For I know the thoughts that I think toward you,’ says Yahweh, ‘thoughts of peace, and not of evil, to give you hope and a future.'"
Let us pray together:
Heavenly Father, we come before You today to lift up ###. She is hurting, Lord, and we ask that You comfort her heart. Help her to trust in Your plan for her life and to seek Your will above her own desires. If it is Your will, Lord, restore the relationship in a manner that brings glory to Your name. But above all, we pray for ###'s peace, understanding, and spiritual growth. In Jesus' name, we pray. Amen.
Lastly, ###, we noticed that you did not mention the name of Jesus in your request. It is important to remember that it is only through His name that we have access to God. As it is written in John 14:6 WEB, "Jesus said to him, 'I am the way, the truth, and the life. No one comes to the Father, except through me.'" If you have not already, we encourage you to put your faith in Jesus Christ and His sacrifice on the cross for your sins.
Prayer Focus: God, Thank You for loving me. Thank You for loving me, Jesus. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, soul, mind, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
