Meaning of when —'s at home in English:

when —'s at home

phrase

British
  • Used to add humorous emphasis to a question about someone's identity.

    ‘who's Peter when he's at home?’
    • ‘The old lady said to tell that to Yuri Gagarin, but the hostess just giggled and said, ‘Who's he when he's at home?’’
    • ‘I say his name and friends reply ’Who's he when he's at home?‘’