To ask for too much; to expect more than is reasonable. An idiomatic expression used when someone makes excessive demands.
そんなに贅沢を言わないで。まずは基本を身につけよう。
Don't ask for too much. First, let's learn the basics.
申し訳ないけれど、贅沢を言わせてもらえば、もう少し大きな部屋がいいです。
I'm sorry to be picky, but if I may ask for a favor, a slightly larger room would be better.
給料が低いのに新車を買うなんて、贅沢を言うようなものだ。
Buying a new car on a low salary is like asking for too much.
君にそんな高価なプレゼントを頼むのは贅沢を言っているかもしれない。
Asking you for such an expensive present might be asking too much.