How does that work? If I sell you a gun knowing you're going to commit murder with it, am I not also morally culpable?
Murder is rights violation - you are in 'contract' by being human in society - you always can be culpable
If you encourage someone to commit adultery, you are morally culpable, just as if you encourage someone to commit murder, you are morally culpable. The only difference is that, in the case of murder, you are also legally culpable.
>If you encourage someone to commit adultery, you are morally culpable
Apparently we just happen to have different views. For me, adultery encouragement is unsympathetic act, but does not fit criteria for being amoral.