Selecting from the given alternatives, fill in the blank in the following sentence with the correct idiom with the meaning 'a treacherous or ungrateful person who has been treated with kindness or trust, but who betrays that trust'.
It was not known to me that he will be a _______ in the long run to have taken to his heels with all my belongings.
Show answer & explanation
Correct answer: C
Explanation
Correct Answer
viper in the bosom
Explanation
The idiom "viper in the bosom" (or "snake in one's bosom") refers directly to a person who betrays the trust, shelter, kindness, or friendship that someone has extended to them. The imagery comes from old fables where a person warms a freezing snake against their chest, only for the creature to revive and bite its savior. In the sentence, the speaker trusted this individual, only for him to steal all their belongings, making "viper in the bosom" the exact match for this act of betrayal.
The remaining options are fictitious combinations designed to mimic real idioms or look convincing. The phrase "snake in the orchestra" does not exist, though it sounds vaguely similar to "snake in the grass" (a hidden enemy). The option "mongoose in the manger" plays on the actual idiom "dog in the manger" (someone who prevents others from enjoying something they themselves have no use for). "Cat on the lap" is merely a literal description with no idiomatic meaning of betrayal.
Key Point
Idioms involving treacherous animals often carry clear narrative origins. When an expression specifically requires the element of extended kindness or intimate trust being violently returned with betrayal, the word "bosom" (signifying close affection and care) coupled with a venomous reptile like a "viper" provides the definitive answer.