We are truly saddened to hear about the situation your friend is in, but we are heartened by your care and concern for him. Let's bring this matter to God in prayer and seek His wisdom and guidance.
Firstly, it's important to acknowledge that the lifestyle your friend is leading is not in accordance with God's will. The Bible tells us to flee from sexual immorality, as it is a sin against our own bodies, which are temples of the Holy Spirit. As it is written in 1 Corinthians 6:18-20 WEB:
"Flee sexual immorality. Every sin that a man does is outside the body, but he who commits sexual immorality sins against his own body. Or don’t you know that your body is a temple of the Holy Spirit who is in you, whom you have from God? You are not your own, for you were bought with a price. Therefore glorify God in your body and in your spirit, which are God’s."
Let us pray for your friend, that God would give him the strength and wisdom to leave his work in pornography and seek a more positive path. Let's also pray for his living situation, that God would convict his heart and show him the need to live in a way that honors God. As it is written in Hebrews 13:4 WEB:
"Let marriage be held in honor among all, and let the bed be undefiled: but God will judge the sexually immoral and adulterers."
Now, let us pray:
Heavenly Father, we come before You today, lifting up our friend to You. Lord, we ask that You would grant him the strength and wisdom to leave his work in pornography. Open his eyes to the harm it is causing him and others, and lead him to a more positive path that honors You.
Father, we also ask for Your guidance in helping him end his current living situation. Convict his heart and show him the need to live in a way that honors You. We pray for the woman he is living with as well, that You would also lead her to a new beginning rooted in dignity and respect.
Lord, we ask that You would reveal Yourself to both of them, that they would come to know You and the true life that can only be found in Jesus Christ.
Finally, Lord, we ask for wisdom and guidance for ourselves, that we would know how to best support our friend during this time. Give us the words to say and the actions to take that would point him to You. It is only by the name of Jesus that we have access to you.
In Jesus' name, we pray. Amen.
Be encouraged, knowing that God hears your prayers and that He cares for your friend even more than you do. Continue to stand in the gap for him, and trust that God is at work in his life.
Prayer Focus: God, Thank You. Thank You for loving me. 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, mind, soul, body, 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. 
