I was PA for 16 years to a family who were a good deal wealthier than these two. I had the use of their card to make online and telephone purchases for them and a chequebook to pay bills, but there is absolutely no way that I would ever have used their money for anything personal, whether they had given permission or not. To do so in that position would be insane - apart from the fact that it would go against every moral instinct I have, even if I had been given permission I would have felt incredibly uncomfortable : a very dangerous path and one which leaves you, the employee, incredibly vulnerable (it so open to misunderstandings or they could deny they gave permission). On top of that, if it all came to grief, all your experience and professional acumen would come to nought because no one would employ you again. A sad story for everyone involved.