中文说－－let one's hair down 和 push one's buttons

在5月19日的报纸‘The Modesto Bee’上看到这么一个句子：
When he really let his hair down, he really had a great sense of humor and when he was really determined he could really mash people's buttons.

句子里的let one's hair down和mash one's buttons中文怎么表达呢？

旧时妇女多数都留有长发。一般人们认为妇女在公共场合应保持端庄稳重的形象，因而如果她们要去参加较为正式的聚会时，就会认认真真地梳洗一番，将头发做成各种精美的发式 wearing their long hair pinned up in a variety of styles 。只有平时在家时才能将头发随意地散下来and taking it down only in the privacy of the bedroom。所以 let one's hair down 就用来表示‘不拘礼节、无拘无束’ to give free expression to one's private views; to behave informally。

Kings and queens can seldom let their hair down. 国王和女王难得有自由自在的时候。

Sally, we've been good friends for a long time. But lately I get the idea you are very much upset with me. I wish you'd let your hair down and tell me what's wrong to make you feel this way.
萨丽，我们多年来一直是好朋友，可最近我感到你对我非常不高兴。我希望你能坦率地告诉我，到底是些什么事使你这么不高兴。

而 mash someone's buttons 在字典里根本查不到。请教了美国人，被告知一般他们用push sb's buttons，一般字典里也没有收录。

折腾半天，在dict.cn上查到是－－使某人行动起来。好不容易又在The Free Dictionary网站searched 到：

to do exactly the right thing to get people to act the way you want.

－－He was an extremely good speaker and knew just how to push an audience's buttons to keep them interested.

Usage notes: also used in the form know what buttons to push:

－－People in your own family know exactly what buttons to push to upset you.

我请教了一美国朋友，他给了一个例子：
Oh, man. He really pushed my buttons ， which means He really made me mad or upset.

(补充：)一朋友从一本八卦杂志上找到一个句子：Brazen beauty knows how to push Baldwin's buttons.（Baldwin是好莱坞的名人。）

push sb's buttons 中文该如何表达？