"Be ye clean, that bear the vessels of the Lord." Isaiah 52:11. The divine method seems to be to make a clear separation between the servants of God and the servants of the world. The privilege of testifying for God or being ambassadors for the Truth is a favor reserved for the Lord's own people. Psalm 50:16, 17 (NET), "…How can you declare my commands, and talk about my covenant? For you hate instruction and reject my words."

Any who serves the Lord needs to live according to God's righteous instructions in the Bible. Preaching righteousness and living sinfully is hypocrisy. 

When you two moved in together ten years ago, you joined your lives and your bodies and became as one. 1 Corinthians 6:16-20 (NIV), "Do you not know that he who unites himself with a prostitute is one with her in body? For it is said, “The two will become one flesh.” But whoever is united with the Lord is one with him in spirit. Flee from sexual immorality…Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price (the precious blood of Jesus). Therefore honor God with your bodies." 

You are already united as one flesh. It would be better to acknowledge your relationship with legal marriage vows. Honor each other by committing your lives to one another in love. Thus, you will be obeying God's instructions and living in holy matrimony. To separate after ten years would be due to hardness of heart, like a divorce. Jesus said, “Moses permitted you to divorce your wives because your hearts were hard." (Matthew 19:8 NIV) Instead, "love one another with a pure heart fervently," 1 Peter 1:22.