Peter,

>>"Sour grapes" is out of Aesop's fables. A fox(!) is trying to reach some grapes high up on a vine and when he can't he says the grapes were sour anyway. IOW it's a mean-spirited response when you don't get what you want.
>
>This site is really good for my English. Thanks, to Dan Freeman too.

These expressions are commonly referred to as "idioms." My wife and I meet once a week with some international students nearby to help them practice English conversation skills. We have a lot of fun explaining such expressions.

For example, someone caught between two difficult alternatives could be said to be "between a rock and a hard place." That might apply in the case of decisions about what to do about VFP now.