Mark 7:21
For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders,
(if it's evil it must be wrong)(fornication)
Acts 15:20
But that we write unto them, that they abstain from pollutions of idols, and from fornication
(abstain from fornication)
Romans 1:29
Being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers
1 Corinthians 6:18
Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
(flee fornication)
1 Thessalonians 4:3
For this is the will of God, even your sanctification, that ye should abstain from fornication
(IFB)