All 4 Uses of

discreet
in
A Streetcar Named Desire

Scudder: I think I impressed him how important it is to handle this thing discreetly.
Scene 2.1

discreetly = in a manner that is unlikely to attract attention or cause embarrassment

Boss: Discreetly, like you handled that operation you done on my daughter, so discreetly that a hillbilly Heckler is shouting me questions about it wherever I speak?
Scene 2.1

...like you handled that operation you done on my daughter, so discreetly that a hillbilly Heckler is shouting me questions about it wherever I speak?
Scene 2.1 *

[T]he two stags, the old and the young one, face each other, panting, Scudder has discreetly withdrawn to a far end of porch.
Scene 2.1

Definitions:

(1) (discreet as in: discreet--not showy or gossipy)
trustworthy with secrets or subtle (not attracting attention)

This sense of discreet sometimes indicates that something is small (so as not to attract attention) as in "discreet earrings."
(2) (discreet as in: discreet--not foolish)
sensible and careful; possibly having good manners

This sense of discreet is more commonly seen in classic literature than in modern writing. There is may also refer to having the judgment to exercise good manners.