Need help connecting two key licenses to the same website

What happens if a BSS site IS stored on Dropbox, and two BSS users try to edit the site at the same time? Will one overwrite the other? Will the file become corrupted? Or will it simply not open on one machine?

This is my exact workflow with my partner in my website business. In our old site builder, we'd store our sites on Dropbox, and then either one of us could work on them, but if we tried to work on the same site at the same time, it would corrupt one of the saved files that kept track of the website, and we'd have to go in and manually change the file name in order to get it to load. So we got into the habit of telling each other over Skype messenger if we were planning to work on a particular site, to avoid conflicts.

I realize that collaborative editing would be a huge undertaking, and probably be impossible without moving BSS to the cloud. Just not practical. I wonder, however, if you could somehow create a version of BSS for teams that could have a live connection via the internet to show if one team member were working on a particular site, and then prevent anyone else from trying to edit that site at the same time.