6. art:I just want you to know that I fired Andrew Tyler that private investigator who gathered all those files. No more snooping. No more trying to control you and the kids.

snoop: 做动词表示调查，名词表示私家侦探，也就是Private Investigator(PI).

7. Aaron: I know Lexi can be a bit much.
erena: Blair Waldorf is my best friend. I can handle "much", but that felt personal.

much: 她可能有点过分，她说话有点恶毒
personal: 这里的意思是说“她完全就是针对我，她对我有意见”，personal就是私人恩怨，冲着某人来的，针对某人。

8. Serena: Well, how long is the enforcer gonna be with this?
Aaron: She's staying with her folks through the holiday.
Serena: So is that Christmas Eve? Or are we talking New Year's Eve or--or maybe Boxing Day?
folks: parents

Boxing Day: a public holiday in the United Kingdom, Canada, New Zealand and Australia, as well as many other members of the Commonwealth of Nations and Greece. It is based on the tradition of giving gifts to the less fortunate members of society. It is usually celebrated on 26 December, the day after Christmas Day, however, its associated public holiday can be moved to the next weekday if 26 December is a Saturday or Sunday.

9. Aaron: Come on. It would mean a lot to me if you gave her a chance, please?
Serena: Okay. Fine. But as long as we're swapping favors here, it'd really make me feel much better about you spending all his time with her if you...I don't know, escorted me to my senior winter dance
Aaron: Fine. You got yourself a deal.

swap favors: 交换条件，互相帮助。注意你要回报别人的恩惠或者帮助的时候，就说return the favor.
escort: 陪伴女性参加舞会，但是有时候escort做名词的时候还有另外一个用法，就是表示prostitute(卖淫)的含义。
You got yourself a deal: 好吧，成交了。注意它跟It’s a deal(成交)的差别在于，用you做主语，更能体现说话者那种无可奈何，处于下风的口气，有点“你赢了”的感觉。