Yes it is most important for women to understand that friction of the victims genital region with THEIR lap is most undesirable.
It causes erotic arousal and fixates the victim on the experience so that in later life they find it undesirable to perform “normal”intercourse without
some recreation of this preliminary.
This can lead to martial problems.
However any position in which the naked genitalia are in contact with ANYTHING:lap,table edge,sofa arm,pillow,even the carpet upon the floor
will have the same rubbing effect on the penis.
Particularly during the rough handling and swaying,struggling,rubbing around that is engendered during a spanking.
So ideally the subject should be free standing or standing erect with no contact at all.