Let sleeping dogs lie
to ignore a problem because trying to deal with it could cause an even more difficult situation
A blessing in disguise
a good thing that seemed bad at first
Beat around the bush
Avoid saying what you mean, usually because it is uncomfortable
Call it a day
Stop working on something
Cut somebody some slack
Don't be so critical
Go back to the drawing board
Start over
Hit the sack
Go to sleep
It's not rocket science
Not complicated
Let SB off the hook
To not hold someone responsible for something
On the ball
Doing a good job
Pull someone's leg
To joke with someone
That's the last straw
My patience has run out
Under the weather
Sick
Add insult to injury
To make a bad situation worse
Bite off more than you can chew
Take on a project that you cannot finish
Don't cry over spilt milk
There's no reason to complain about something that can't be fixed
