得了吧。（Déle ba.） Give me a break./ Come on.

用法说明
这句话常用来否定对方所说的内容，表示说话人不同意对方的话。意思是：快别说了，才不是呢。强调事实不是对方所说那样的，而是另外一种情况。
Meanings
This expression is used to negate the other and show one's disagreement, meaning "don't say that; it is not what you think". It indicates the truth is not as the speaker assumed but is a totally different situation.

例句
Sentences
Jiă: Zhāng Lán zhēn shì zánmen bān zuì piàoliang de nǚshēng.
甲：张兰真是咱们班最漂亮的女生。
A: Zhang Lan is really the most beautiful girl in our class.

Yǐ: Déle ba, Liú Fāng, Mǎ Lì, nǎ yí gè bù bǐ tā hǎokàn a?
乙：得了吧，刘芳，马丽，哪一个不比她好看啊？
B: Come on. She is not even as pretty as Liu Fang and Ma Li.

Jiă: Tīngshuō nǐ yǒu nǚ péngyou le? Hái shì gè yīshēng?
甲：听说你有女朋友了？还是个医生？
A: I heard that you have a girlfriend now, a doctor!

Yǐ: Déle ba, wǒ xiànzài háishì guānggùnr ne.
乙：得了吧，我现在还是光棍呢。
B: Give me a break. I'm still single now.

原文链接