The fact that it does 'live forever' is exactly why the vast majority of escorts won't have any interest in you recording the session, whether faces are shown or not.
There are plenty of videos made by couples for private viewing that have found their way onto the internet, I doubt very many will be happy with a stranger filming them.
If you want a session to live longer you'll have to rely on your memory, or arrange to see the lady in question again.
"Nothing is funnier than unhappiness" - Samuel Beckett