Look its very simple:
As of May, I will own space at SSR and Edward will have space at BCV.
Today, I can call and see if Edward chose to book his place at BCV. He didnt, so I book his place. The fact that he has to wait to call and see if i have booked my place, does not change the fact that it will be vancant, because I am not staying at my place, Im staying at his. So my place is available for his use.
As of May, I will own space at SSR and Edward will have space at BCV.
Today, I can call and see if Edward chose to book his place at BCV. He didnt, so I book his place. The fact that he has to wait to call and see if i have booked my place, does not change the fact that it will be vancant, because I am not staying at my place, Im staying at his. So my place is available for his use.