-what? are you kidding? i am still a bachelor.
-so who is that girl walking along the street with you yesterday?
-my god! she is my sister and she has got married and her baby is 5 years old!
-wow, your sister looks so young. 2） No kidding! 我不是在开玩笑.=I am serious! example: -Andy, you didn't pass the exam!
-I know you are kiddding.
-No kidding.