at the expense of

at the expense of は「何とかの犠牲の上に」くらいの意味です。6:31 that's a good time? at somebody else's expense? 面白いだと？ホームレスをいじめて？how about I have a good time at your expense? じゃ俺が、お前らをいじめて面白がろうか？

Teens Harrass And Humiliate the Homeless | What Would You Do? | WWYD
https://www.youtube.com/watch?v=q9Ap0aRUx8E  1:35 the rush to meet deadlines has come at the expense of safety. 工期に間に合わせるために工事を急ぐのは安全を犠牲にするという代償が伴う。
China Bullet Train Crash Cover-Up?
https://www.youtube.com/watch?v=MyC420hA_9Y  2:34 getting that housing at the expense of those of us who have lived here for decades or who were born and raised here. サンフランシスコに集まったIT企業のリッチな若者たちはここで生まれ育った人やこの地に長く住んでいた住民を押しのけて自分たちの住処を確保する。
Going to San Francisco? Take some Google glasses
https://www.youtube.com/watch?v=AXwtJTT2zuk  1:16 it's designed to make us feel good at our own expense. 国が国民の税金を使って、いかに国が頑張っているかをアピールしているのは、自腹を切って、自分を喜ばせているようなものだ。
Rick Mercer: Rant: Canada's Economic Action Plan

練習問題解答
a-3158 at the expense of
a-5462 at the expense of
b-2124 at the expense of