I'm not really sure what the question is here. One dog is not informing the other dog about potty Breaks. There may be some ranking issues among the two. Not everydog catches on that, if I stand by the back door, someone will let me out, on their own. Walk the dogs on a regular basis, or let them out on a regular basis so they will need to go out at those times. Create habits.
When I look up into the sky, I think to myself, Wheres the ceiling?