"at someone's expense" is correct and usable in written English.
It is used when someone is victimized or taken advantage of for the benefit of another person. Example: The boss took advantage of the intern, making them work overtime without pay at their expense.
At times, as when she impersonates Piaf or Mariah Carey, it's easy to imagine that Camille is having fun at someone's expense – but she insists that these songs are also celebrations of singers she greatly admires.
Steven Wright said the only suggested cut was a joke at someone's expense.
She said, "There are many funny stories, but I've realized that almost all of them are at someone's expense.
Universities used to tell students to go out and get experience in the workplace, learning at someone's expense, before thinking about starting their own firms.
Having a charismatic murderer as your protagonist is an inversion of the traditional primetime hero; Tony Soprano has made that identity more his own, but where The Sopranos won many of its fans through its mawkish comedy, poking fun at the banalities of mob life, laughs in The Shield are far less frequent and almost always at someone's expense.
Prior to the release of the video, Jocelyn Vena of MTV predicted that the video of "Mean" will be "a honky-tonk-type performance video, in which [Swift] and her band have a little fun at someone's expense".
Players are constantly on at each other, having a joke at someone else's expense – it's seen as an initiation process.
His gain does not have to come at someone else's expense, and someone else's gain does not mean he has to lose something in the bargain.
He has a variant on the survivor's complex; a pressing sense that he's got where he is at someone else's expense.
In over an hour's conversation, it's the closest he offers to a comment at someone else's expense.
It's great that King is getting attention, but it's unfortunate that her popularity is at someone else's expense. .
