Sit (up)on hot cockles phrase
To be angry at someone/something, because you have to wait for a long time.
I'm sitting on hot cockles because I've been waiting for John for 20 minutes, but there is no sign showing he is coming.
We all sat on hot cockles when the teacher kept making comments on our tests instead of giving them back to us.
Can't wait to do something
The verb "sit" must be conjugated according to its tense.
The origin of this phrase is not clear.