To "behave oneself" in social situations in English is a common way to say this in English. This phrase comes from the verb "behave," which means to conduct oneself in a particular way. For example, you can say "I always try to behave myself in social situations" or "I was raised to behave myself in public." Here are a few examples of this phrase in action:

"Please behave yourself at the party tonight." (请在今晚的聚会上表现得体。)

"My parents always expect me to behave myself when we go out in public." (我的父母总是希望我在公共场合表现得体。)

"I try to behave myself in meetings at work, but sometimes it's hard to stay focused." (我试着在工作中的会议上表现得体，但有时很难保持专注。)

In general, this phrase is used to remind someone to act in a polite and appropriate way in social situations. It is often used by parents to remind their children to behave, but it can also be used among adults in a variety of social situations.