Idiom: "goody-goody"
Definition:
someone who is self-righteously or smugly good
Examples:
1) Goody-goodies love to compliment their teachers on their teaching.
2) Sam is a real goody-goody. He always does the boss’ laundry.
中文解释：http://www.youzienglish.com/main/idiom_of_the_day/goody_goody/cn/
