There are two ways to lie, omission and comission, either way it is a lie. I believe that your comment about you and your sister living in La,La Land may have some validity. Have you considered one to one therapy to address this issue and others?
I too would give some serious consideration to how your husbands manipulation is having an adverse effect on your son, he learning that manipulation and lieing is acceptable, your son is being used a pawn between you and your husband. And, you find humor in it, must be me, I don't see any humor in this game.
All that aside, I do wish you the best, hopefully you will get the help that you need.