夜更かしなど平気だ。

tbd

Staying up late nights is nothing to me.

平気だよ。

tbd

没事！

没关系。

I'm fine.

I'm cool with that.

彼は平気でこの企てを試みた。

tbd

No scruple held him back from making this attempt.

彼は平気でうそをつく。

tbd

He has no scruples about lying.

彼は病気など平気だと思っている。

tbd

He thinks nothing of his illness.

彼は自分の思い通りにするためなら平気で人もあざむく。

tbd

He is not above deceiving others to get his way.

彼が行ってしまおうといようと私は平気だ。

tbd

I don't care whether he leaves or stays.

他留下或者離開也不關我的事。

遅くまで音楽かけているけど、ご近所さんは平気？

tbd

Is loud music OK with the neighbors at this hour?

昔は、平気で昆虫触れたのに、今は、図鑑を見るだけでもだめ。

tbd

When I was a kid, touching bugs didn't bother me a bit. Now I can hardly stand looking at pictures of them.

人が何を言おうと平気だよ。

tbd

I don't care what people say.