discretely

There are lenses discretely built in watches, ties, cigarettes, lighters, and other forms of disguise.

Kerry is positioned to put an American thumb on the scales discretely, with the president's support.

They hear the happy talk and they shake their heads or roll their eyes (discretely) and wonder what these people are smoking.

If science is discretely silent about these things, what can the more venturesome and less responsible imagination suggest?