Definition of that would be telling in English:

that would be telling

phrase

informal
  • Used to convey that one is not prepared to divulge confidential information.

    • ‘Last year, my gifts were mostly made up of all the books that had inspired me in the previous year, coupled with small cartoon-like cards; and this year… well, that would be telling.’
    • ‘There's even a sweet mystery to be had in the form of… but that would be telling.’
    • ‘‘Now that would be telling,’ she grinned as she took a seat beside Kaye.’
    • ‘Well, that would be telling now, wouldn't it?’
    • ‘‘One of them is quite famous but that would be telling,’ Tim teases.’
    • ‘The old man smiled and winked, ‘now that would be telling!’’
    • ‘As for replying to your wonderment over whether or not Jesse's fallen for Will just a little bit… well, that would be telling.’
    • ‘And that would be telling… Plus I'm not sure yet.’