Please read the Word of God in 2 Corinthians 6:14-18
It says that we are not to yoke with unbelievers. It's referring to relationships whether it be dating, marriage, business partnerships, close friendships/buddies, any relationship that ties you with another who is an unbeliever. It explains in that Scripture that we are to "come out from among them and be separate."
We are called to love the unbeliever as Jesus did by being an example, by living in a godly way as a light to them, and we are to pray for them. But yoke ourselves to them we are told explicitly not to do.
I praise God for giving you wisdom in separating from that unbelieving man, that you have separated yourself to Jesus Christ. Glory to God! \
/ And I pray for that man, that the Lord would open the eyes of his heart to repent and be saved. Only God can call him and save him, but we can pray for him.