@LukeAlmighty you have marked both "sex outside of marriage is a sin" and "atheist." How does that work?
@sjw
You know that I don't believe that God exists.
So, what is the real question?
@LukeAlmighty that is the question. Sin is what it's called when you break the rules of a religion. Actual atheists have no religion and thus cannot commit sin in their own eyes.
@sjw
They can commit the same actions, and see all the results the action causes in this world.
We don't believe in the judgement after death, but all of the sins are destructive in here too.
@sjw
*With one obvious exception ;D
@LukeAlmighty okay now explain why wearing garments made of two different types of fabric woven together is bad for society
@sjw 
Yeah... I wouldn't be able to mark that one as a sin
Morality and sin are two different things.