The last straw.
The last straw.
The last straw" is from the proverb "It's the last straw that breaks the camel's back," highlighting how a minor additional burden or problem—like a single straw added to a loaded camel—can cause a sudden loss of patience or collapse after a series of other burdens.
His late arrival was the last straw for her patience.
Her patience was exhausted when he arrived late.
Forgetting her birthday was the last straw in their relationship.
Forgetting her birthday ended their relationship.
When he accidentally spilled coffee on her project report, it was the last straw, prompting her to request a new partner.
Her partner's accident with the project report prompted her to ask for someone new.