Idiom Requests – Seeking Idioms or Phrases for an Obvious ‘No’

There is the term choking in psychology. It is performing worse under pressure or if you are expected to perform well. It is also mentioned that, if you are being watched when you are performing a task, it means that performing well in this task is important. Thus, people perform worse.

The term choking is usually used in sports but you can choke in social interactions or anywhere.

Below is an explanation of choking and an example from the book "The Curse of the Self : Self-Awareness, Egotism, and the Quality of Human Life" By Mark R. Leary Professor of Psychology Duke University (2004).

Social loafing is a related term also. It is not exactly about being watched but you perform less when you are in a group or if there are people around.

In the social psychology of groups, social loafing is the phenomenon of people exerting less effort to achieve a goal when they work in a group than when they work alone.

http://en.wikipedia.org/wiki/Social_loafing

top off

: to finish something appropriately: The couple topped off the romantic evening with a walk along the river. The American Heritage® Dictionary of Phrasal Verbs

: to end or terminate something (with something). They topped the building off with a tall flagpole. McGraw-Hill Dictionary of American Idioms and Phrasal Verbs

wind up

: to bring something to a finish; end something: We need to wind up this project before January. This card game is fun, but let's wind it up before dinner.`The American Heritage® Dictionary of Phrasal Verbs

wind down

: to end or cause something to end gradually The storm finally began to wind down after four hours of heavy rain. We wound down our affairs in Europe and left for home. Cambridge Dictionary of American Idioms