a question needs to be answered

[fruitcakes]

At the expense of , in the inexpense of, on the expense of
Which is correct?

 

[Barb_D]

I think you mean "at the expense of."

The report was finished on time, at the expense of my date with my husband, because we stayed until midnight to complete it.

Is that what you mean? It "cost" something else to achieve the first thing.

 

[fruitcakes]

Yes, that's what I mean. Can I say "in the expense of" or "on the expense of" ? I think I've read them somewhere.

 

[bhaisahab]

Yes, that's what I mean. Can I say "in the expense of" or "on the expense of" ? I think I've read them somewhere.

I can't think of any possible use for "in/on the expense of".