地じ雷らいを踏ふむ

expression, godan verb (-mu)

step on a landmine

Literal meaning: physically stepping on an explosive landmine.

• 戦せん場じょうで兵へい士しが地じ雷らいを踏ふんでしまった。

  A soldier stepped on a landmine on the battlefield.

expression, godan verb (-mu)

really step in it; screw up; open a can of worms

Idiomatic: to blunder into a sensitive topic or situation, causing trouble or embarrassment.

• 彼かれの前まえで離り婚こんの話はなしをするなんて、地じ雷らいを踏ふんだよ。

  Bringing up divorce in front of him was really stepping in it.

• 会かい議ぎでその質しつ問もんをしたら、地じ雷らいを踏ふんでしまった。

  I opened a can of worms when I asked that question at the meeting.