1. 你在开玩笑吧!

[ nǐ zài kāi wán xiào bā ! ]

Are you kidding?

2. 哦，你别拿我开玩笑了。

[ ò ， nǐ bié ná wǒ kāi wán xiào le 。 ]

Oh，you are kidding me.

3. 他最喜欢开玩笑。

[ tā zuì xǐ huān kāi wán xiào 。 ]

What he likes best is making jokes.