[swear|curse] a blue streak

to use offensive words in an intense and rapid manner

The idiom "swear a blue streak" originated from the idea of using profanity or vulgar language with such intensity and rapidity that it creates the impression of a continuous stream of blue (vulgar) language. Figuratively, it is used to refer to the act of expressing extreme anger, frustration, or annoyance by using a rapid and continuous string of curse words.

When the car broke down again, John cursed a blue streak, venting his frustration at the never-ending mechanical issues.
After losing the game in the final seconds, the coach swore a blue streak, expressing his disappointment and anger at the team's performance.
The customer became increasingly frustrated with the poor service and began to swear a blue streak, demanding immediate resolution to the issue.
When the computer crashed and wiped out hours of work, Jane swore a blue streak, unable to contain her frustration and anger.
The politician, during a fiery debate, started to curse a blue streak, using aggressive language to attack his opponent's policies.