Perhaps you would join me for a nightcap?

或许你能和我一起喝杯睡前饮料？

《柯林斯英汉双解大词典》

An old man in a nightcap opened the window and looked out.

一个戴睡帽的老人打开窗户向外望去。

youdao

Did you two have a nightcap?

你们两睡前小喝一杯了？

youdao

And, if so inclined, a tumbler of gin, whisky or brandy as a nightcap.

ECONOMIST: Dieting

Back at the house, Tom and Roger are having a drink in the living room, a nightcap and a cigar.

NEWYORKER: Brother on Sunday

After collecting a nightcap in the Club Lounge, we contentedly returned to our corner suite, embellished with oil paintings, fresh flower arrangements, leather ottomans, a dramatic half-tester king bed and mirrored French armoires.

FORBES: Maison Orleans: A Crescent City Gem