meaning in context - In what occasion could the word “precious” be taken disapprovingly, or sarcastically?

I understand that the word “precious” in the following quote of Maureen Dowd’s article “Heart of Darkness” (NYT, March 20) literally means “2. valuable or important and not to be wasted” as defined in OALD:

Congressman Jones read an e-mail from a former boss of General Allen’s, giving the congressman this unvarnished assessment: “Attempting to find a true military and political answer to the problems in Afghanistan would take decades. Would drain our nation of precious resources, with the most precious being our sons and daughters. Simply put, the United States cannot solve the Afghan problem, no matter how brave and determined our troops are.

But I didn’t know “precious” has another meaning as defined in OALD: 5. (disapproving, people and their behavior) very formal, exaggerated and not natural, and Readers English Dictionary: 2.(colloquial) terrible, almost worthless, until I was told by my respected forum mate a few days ago.

Being encouraged by his suggestion for me to “ask another question if I’m not sure of what he means by describing his input as “precious” is actually rather “precious” phrasing, I would like to ask:

1. 
   

   What is an example of “precious” being used as “disapproving” or sarcastic way (as neither OALD nor CALD provides examples)?

   
   


2. 
   

   Is there an easy way to discern the instance “precious” being used as “disapproving” from the case being used in the sense of genuine “great value” as used in the above quote other than judging from the context?

   
   

Answer

Precious is used disapprovingly when someone is behaving in a way others perceive to be over-sensitive. In other words, they are behaving as if they are precious.

For example:

Dave: "I can't possibly get in your car, it smells faintly of dog"
Susan: "Oh stop being so precious and get in"

Another example of using precious disapprovingly is in the phrase precious language (as explained by TimLymington and FumbleFingers in the comments). This is attributed to language that is used in a way that is overtly laboured over, which would imply that the speaker/writer thinks a lot of themselves, and is trying to show off in some way. For example:

The warp and weft of our frail and meagre existence is inauspiciously blanketed with disheartening, disquieting, disingenuous and discourteous vociferations that we must yield our material being to the dogmatic and obtusely inconsequential media

An example of using precious sarcastically is when a child is behaving precociously:

Child doing something precocious

Parent: "Oh isn't Tristan precious!" (not sarcastic, genuine praise for their child)

Onlooker who finds the scene sickening: "Oh yeah. Really precious." (said in a sarcastic tone, probably out of earshot of the parent)

It would be difficult to discern a sarcastic use of precious without hearing the tone of voice, or knowing the person saying it.