一いっ線せんを越こえる

ichidan verb, expression

cross the line; go too far

Idiomatic expression for overstepping a moral, social, or personal boundary. Often used when someone does something unacceptable or violates a norm.

• 彼かれの冗じょう談だんは一いっ線せんを越こえていた。

  His joke crossed the line.

• あの政せい治じ家かの発はつ言げんは一いっ線せんを越こえたと思おもう。

  I think that politician's remark went too far.