Sex is just well sex Fornication as in fûcking everything you see that's basically the sin or whatever the fûck you want to call it. Sex is creating life and the reason I think just fûcking is considered a sin would be because you're in a way perverting the intention of it which is to create a bond with a soulmate so to speak. P.S. Not a Christian and never will be after seeing the church for what it is a prison for your mind and a way for sociopaths to steal your money.