in the what ?

Friday night, helped out at my friends' restaurant as they were short-staffed. Finished later than expected, so a little after midnight S called my cell phone to make sure I was OK and wouldn't miss the last metro home.

- Where are you ?
- I'm almost home, I'm in the staircase. (quietly, as voices carry in this old building)
- You're where ?
- In the staircase.
- You're what ?
- I'm here, in the staircase !
- puzzled silence. What ?
- Open the door, I'm right here !

The door opens. Laughter.

He thought I had said "I'm in the suitcase."

It's a good thing he's learning French. We'll now be able to miscommunicate in 2 languages instead of just one.