Bite one’s tongue字面解释是“咬到自己的舌头”，这个短语是什么意思呢？请看对话：

A: I have an announcement to make.

B: Yes?

A: I’m getting back together with my ex-boyfriend, Bobby.

B: Really? Is this the same ex-boyfriend who dated your sister?

A: Yes, but he loves me again.

B: …

A: What?

B: I’m biting my tongue.

Note: When a person bites his or her tongue, he or she is trying hard not to say something, especially in order to avoid saying something inappropriate or likely to cause a dispute. In this case, the second speaker is trying hard to hold back “I think you’re an idiot.” People also say “hold one’s tongue” to mean the same thing.