"Hold it in" is a phrase in English that means to control or restrain oneself from expressing or releasing something, typically an emotion or bodily function. Here are a few examples: "When I heard the news, I had to hold in my tears until I got home." "I had to hold in my laughter during the serious meeting." "It's not good for your health to hold in your anger all the time." "I really need to use the restroom, but I'm trying to hold it in until we get to the next rest stop." In each of these examples, the speaker is trying to control or restrain something, whether it's their tears, laughter, anger, or bodily functions, until an appropriate time or place.

哭出来吧，别忍着。 Don‘t hold it in.