Meaning of the word "cross the line" in English

What does "cross the line" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

cross the line

US /krɔs ðə laɪn/
UK /krɒs ðə laɪn/
"cross the line" picture

Idiom

to go beyond what is acceptable or appropriate

Example:
His jokes were funny at first, but then he started to cross the line.
You really crossed the line when you insulted his family.