"The body is not meant for sexual immorality, but for the Lord, and the Lord for the body. And God raised the Lord and will also raise us up by his power. Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a prostitute? Never! Or do you not know that he who is joined to a prostitute becomes one body with her? For, as it is written, “The two will become one flesh.” But he who is joined to the Lord becomes one spirit with him. Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body." - 1 Corinthians 6: 13-20

What is sexual immorality? Sexual immorality is any sexual act that occurs outside of the biblical definition of marriage.