Minnie tells Donald that if he doesn't get a condom that they can't have sex but suggests to Donald that he go buy a condom. She says that maybe they sell them at the front desk. Donald proceeds to go downstairs and gets to the front desk. He asks the hotel clerk if they sell condoms.
The clerk says "yes we do" and pulls one out from under the desk and gives it to Donald. The clerk asks "Would you like me to put that on your bill?" and Donald says, "NO! WHAT DO YOU THINK I AM, SOME KIND OF PERVERT?"
IF YOU DIDN'T GET IT:
The clerk meant account of charges for "bill"
Donald meant bird's beak for "bill"