He tried hard not to smile in smug self-satisfaction.

他强忍住沾沾自喜的笑容。

《柯林斯英汉双解大词典》

Men in the room tried not to smile, avoiding eye contact with the women, but some actually smirked .

气氛变得很尴尬。等候室的男性家属忍住不笑，避免接触到女性家属的眼神，但还是有些人不太自然地在偷笑。

youdao

Clare gets up and goes back to her side of the table. She sits up straight and tries not to smile.

克莱尔起身回到自己的座位，直挺挺地坐着，努力不微笑。

youdao

So, he writes: To the psychologist alone can such questions occur as: Why do we smile when pleased and not scowl?

他这样写到：,对哲学家本身说,会出现这些问题：,为什么开心时我们微笑而非皱眉？

耶鲁公开课 - 心理学导论课程节选

And he's not really very happy as opposed to a smile like this, which is a real smile.

他并不是很高兴,相反的是这样的微笑，这是真正的微笑。

耶鲁公开课 - 心理学导论课程节选

When they told me the team, I tried not to smile too big in the office.

WSJ: Yankees complete trade for Vernon Wells

Try not to smile when you think of a freshly-shoveled walk, or when the roses seem to multiply overnight.

FORBES: How Would I Behave If I Were Happy

You have to admire how that is pulled off so deftly and quickly - screenwriter Avril E Russell has a very good light touch - and it's impossible not to smile at it.

BBC: Babyfather plays with stereotypes