that would be telling Идиома
I'm telling you|tell
informal It is important to listen to what I am saying.
Marian is a smart girl but I'm telling you, she doesn't always do what she promises.
you're telling me|me|tell|telling|you
interj.,
informal 
Used to show that a thing is so clear that it need not be said, or just to show strong agreement.
"You're late." "You're telling me!" Compare: YOU BET, YOU SAID IT.
no telling
no telling see
there's no telling.
there's no telling
there's no telling It's impossible to determine, as in
There's no telling how many children will come down with measles, or
There's no telling what will happen in the next episode of that soap opera. This idiom uses
telling in the sense of “reckoning,” a usage dating from the late 1300s.
you're telling me
you're telling me I'm well aware of that, as in
She's a terrific dancer.—You're telling me! I taught her how, or
You're telling me, the prices are sky-high here. [Early 1900s]
that would be telling
That would accord abroad the abstruse or surprise. A: "Does this beggarly that we're accepting a puppy afterwards all?" B: "Now, now, that would be telling. Just accept patience!"Learn more: telling, thatthat would be telling
that would be acknowledgment arcane information. informal 2000 Imogen Edwards-Jones My Canapé Hell ‘Are you propositioning me?’ I say, attempting to attending annoying in my Devonshire home-knit and Angora Dutch cap. ‘Now that would be telling,’ he smiles. Learn more: telling, that