buy a round
buy a/the round (of drinks)
To buy drinks, especially alcoholic ones, for each person in a group. "Next" is commonly used before "the round." If your new friend is buying us a round of drinks, then I like him already! OK, who's buying the next round?
Farlex Dictionary of Idioms. © 2022 Farlex, Inc, all rights reserved.
buy a round (of drinks)and buy the next round (of drinks)
to buy a drink for each person present, with the expectation that one or more of those persons will later do likewise. Which one of you guys is going to buy the next round?
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.