Tell you the truth:

跟你說實(shí)話

例句：  

To tell you the truth, I was afraid to see him. 

跟你說實(shí)話，我怕見到他。

Truth be told:

實(shí)話實(shí)說

例句：

Truth be told, you are no match for me.

說句實(shí)話，你不是我對(duì)手。

Be straight with you:

跟你說實(shí)話

例句：     

I respect your honesty, so I'll be straight with you, too. 

我很敬重您的誠(chéng)實(shí)，所以我也會(huì)跟你實(shí)話實(shí)說。

Song for you（片尾曲）

adele - rolling in the deep jamie xx shuffle