回答

・It's bad manners.
・It's bad-mannered.

「不好的行為」可以用英語 It's bad manners. 或 It's bad-mannered. 來表達。

It's bad manners to eat with your hands. stop it.
（用手吃飯是不好的行為。請不要這樣。）

I thought it was bad-mannered, but I was very hungry, so I ate the bread on the spot.
（我雖然覺得這是不好的行為，但我實在太餓了，就當場把麵包吃掉了。）

很開心能對你有幫助。

有幫助｜0