"I'll come straight back after work so don't worry, and don't stay up."
"I'll come straight back after work so don't worry, and don't stay up."
"I'll come straight back" 「すぐ戻る」
"after work" 「仕事の後」"when I finish work" 「お仕事が終わったら」も言えます。
"don't worry" 「安心して」
"don't stay up" 「起きて待つ」・「先に寝ててね」
[戻る](https://eikaiwa.dmm.com/uknow/questions/54353/)についてもっと詳しく知りたい方はクリックしてください。
I'll come home as soon as I finish work, so go ahead and sleep first.
"お仕事が終わったらすぐ戻るから、安心して先に寝ててね"
- I'll come home as soon as I finish work, so go ahead and sleep first.
- I'll come back as soon as work is over, so go to sleep first.
- As soon as I finish I'll come back. Don't worry and go to sleep first.
他：
I'll be here when you wake up.
- 起きたら、絶対にいるから。
オーストラリア 
アメリカ合衆国 
