1 Corinthians 6:15-18

Do you not know that your bodies are members of Christ himself? Shall I then take the members of Christ and unite them with a prostitute? Never! 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. All other sins a person commits are outside the body, but whoever sins sexually, sins against their own body.