We are saddened to hear about your son's situation, but we are encouraged by your faith and your desire to seek prayer for him. We stand with you in praying for his relationship and his personal walk with Christ.
Firstly, let us address the issue of your son being in a relationship with someone who is not a believer in Christ. The Bible is clear about this in 2 Corinthians 6:14-15 (WEB), "Don’t be unequally yoked with unbelievers, for what fellowship do righteousness and iniquity have? Or what fellowship does light have with darkness? What agreement does Christ have with Belial? Or what portion does a believer have with an unbeliever?" We pray that God will reveal the importance of being equally yoked to your son and guide him towards a relationship that honors Him.
We also want to point out that true satisfaction and contentment can only be found in Christ. As it is written in John 4:13-14 (WEB), "Jesus answered her, 'Everyone who drinks of this water will thirst again, but whoever drinks of the water that I will give him will never thirst again; but the water that I will give him will become in him a well of water springing up to eternal life.'" We pray that your son will experience this living water and find his heart's desires satisfied in Jesus.
Let us pray together:
"Dear Heavenly Father, we come before You today to lift up Thulinulan's son. Lord, we ask that You reveal Yourself to him in a powerful way. Help him to see that You are the true and living God, and that only You can satisfy the desires of his heart. We pray that You will draw him out of this unequally yoked relationship and guide him towards a godly partner who shares his faith. Protect him from temptation and help him to resist it. Fill him with Your Holy Spirit and let him encounter Jesus in a life-changing way. In Jesus' mighty name, we pray. Amen."
We encourage you to continue praying fervently for your son and to trust that God is working in his life. Remember the promise in 1 John 5:14-15 (WEB), "This is the boldness 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." Keep asking according to God's will, and trust that He hears you.
Lastly, we note that your request does not mention the name of Jesus Christ. We want to remind you that it is only through Jesus 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.'" We encourage you to always pray in the name of Jesus, as it is the name above all names (Philippians 2:9-10).
Articles:
Let's lift up Dweryall seeking guidance and restoration in marriage. Trusting Jesus for wisdom and comfort. "Come to me, all you who are weary and burdened, and I will give you rest" (Matt 11:28). Praying for strength and faithfulness in this storm. In Jesus' name! 
Let's lift up @Anonymous for emotional peace, @Kensem for a loving partner, @Dweryall for marriage restoration, @Fietown for their kitten's safe return, and @Smilee for healing. Please join in prayer for these needs. 
@Rhuolparn's dad is having open heart surgery. Let's pray for successful surgery and comfort.
@Craenond needs prayers against miscarriage.
@Kensem is seeking prayers for marriage and family.
@Vngoirath's dog Tiger needs healing.
@Anonymous could use prayers for peace of mind.
Syliuthor:
Let's lift up @Puasor who's battling anxiety.
@Powers needs protection for their family.
@Zietsorwell is dealing with dental insurance issues.
@Bwooxmore's family is battling COVID.
