last straw

The final problem, setback, or source of irritation in a series that causes one to finally lose patience or for something to stop working. A shortening of the proverb "it is the last straw that breaks the camel's back." I've been a good sport about letting Tom share the credit for my work, but this is the last straw! I'm finally going to expose him for the liar he is. OK, that's the last straw, kids! I told you to stop shouting back there, and now I'm turning this car around.

the final difficulty in a series; the last little burden or problem that causes everything to collapse. (From the image of a camel being loaded down with much weight. Finally, at some point, one more straw will be too much and the camel's back will break.) When our best player came down sick, that was the straw that broke the camel's back. We hoped to make the playoffs, but lost all the rest of our games. When she showed up late a third time, that was the straw that broke the camel's back. We had to fire her.

The final minor irritation; one last superfluous item. This term, also put as the straw that broke the camel’s back, appears in Dickens’s Dombey and Son (1848). It is a version of the earlier “last feather that breaks the horse’s back,” found in Archbishop John Bramhall’s Works (1677) and repeated in Fuller’s Gnomologia (1732). Both convey a vivid image of something that would not be burdensome if there were not too much of it, but the straw version is the one that survived and became a cliché.