Idiom: "(to) make a fool of oneself"
Definition:
to cause oneself to look stupid
Examples:
1) Jen got drunk at a party and made a fool of herself.
2) Stop yelling in public! You’re making a fool of yourself.
中文解释: http://www.youzienglish.com/main/idiom_of_the_day/to_make_a_fool_of_oneself/cn/