She hesitated to explain any further because, she said, “TLC has kind of told us to hush-hush.”
Escorting is big business on the straight side too, only more of a hush-hush operation.
She's willing to speak about things people might to keep on the down-low or hush-hush.
Very secret; classified: a hush-hush border meetingnoun
: Why all the hush-hush about Walden? (1916+)