A clumsy denial resulting in self-exposure

Len and Jim worked for the same company. One day, Len lent Jim $20, but then Jim left his job and went to work in another town without paying Len back his $20.

Len did not see Jim for a year, and then he heard from another friend that Jim was in town and staying at the Central Hotel, so he went to see him there late in the evening.

He found out the number of Jim's room from the clerk at the desk downstairs and went up to find him. When he got to the room, he saw Jim's shoes outside the door, waiting to be cleaned.

'Well, he must be in,' he thought, and knocked at the door.

There was no answer.

He knocked again. Then he said, 'I know you're in, Jim. Your shoes are out here.'

'I went out in my slippers.' answered a voice from inside the room.