at one's expense
01
used to say who has paid for something
Idiom
例
The document was printed at the taxpayer's expense.
The tour is free, but all meals are at your own expense.
02
(particularly of a joke) in a way that causes harm to someone or makes them embarrassed
DisapprovingIdiom例
He told a joke at her expense, which left her feeling humiliated in front of the entire group.
Making fun of his appearance during the presentation was completely uncalled for and hurtful — it was humor at his expense.
