It takes two to tango

Birds of a feather flock together - means that people of the same sort or with the same tastes and interests will be found together

once in a blue moon means very rarely

Until you are blue in the face

no news is good news

a red flag

at the back of your mind, you are thinking about it or it is affecting how you behave

To pull the plug on something means to stop, to discontinue, to terminate

At your fingertips = available, accessible, ready to be used

A show of hands is an occasion when people in a meeting vote by putting their hands up (to indicate whether they vote yes or no) Example: The dispute was settled with a show of hands.