"I have my wife at home. It is difficult for all of us"
The Brothel
Public DomainThe Brothel - Credit: Vincent van Gogh

The German officer may have assumed Charlotte, alone in a hotel, was a prostitute.  During the Occupation, the top brothels in Paris were reserved for German officers and French collaborators. Herman Goering, head of the Luftwaffe, was a visitor to Le Chabanais, a famously luxurious establishment.