expression, godan verb (-mu)
step on a landmine
Literal meaning: physically stepping on an explosive landmine.
戦場で兵士が地雷を踏んでしまった。
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.
彼の前で離婚の話をするなんて、地雷を踏んだよ。
Bringing up divorce in front of him was really stepping in it.
会議でその質問をしたら、地雷を踏んでしまった。
I opened a can of worms when I asked that question at the meeting.