大概一百多年以前，一些有钱的人往往化很多钱去买一只稀有品种的小狗来显示自己很有钱。一些阔太太们经常在接待客人的时候把一只小狗抱在腿上来眩耀自己的阔气。因此，put on the dog引申为炫耀,摆阔，装腔作势。

【例句】
My wife always feels like she has to put on the dog whenever my parents come to visit.
我妻子总觉得当我父母来的时候，她必须得装腔作势。

But what I like about him was that he never put on the dog to show off his money.
我很喜欢这个朋友，因为他从来也不炫耀自己多么有钱。