To put your foot in it 的意思是“说走嘴了”，结果使得局面变得尴尬或不愉快。也可以用来表示不小心把秘密说了出来。
I really put my foot in it when I asked where his girlfriend was. I’d forgotten she’d left him.
You put your foot in it when you mentioned the party on Saturday! It was supposed to be a surprise.
另一个短语 to put your foot down 表示一个人态度坚决，对一件事情到底是做还是不做立场坚定，不予让步。
From now on I’m putting my foot down. I expect all assignments to be submitted no later that 5pm on deadline day, OK?
Dad put his foot down and refused to let me use the car until I pay for the damage I caused last time I borrowed it.