try this next time you are having dinner with someone: gradually move objects on the table over to their side.
your cell phone, the napkin holder, condiments, menus, whatever works. just move them ever so gradually over towards their side of the table over the course of the meal. make sure to leave yourself all the room in the world on your side of the table as well.
you should notice that person become noticeably uncomfortable and then start moving the objects back to your side without even knowing they are doing it or why they are doing it.
i did this to my wife for a while before letting her in on it, now she does it to her family at meals and we laugh when they move stuff.