tell you the truth
(idiomatic, informal) Used to positively assert the frank honesty of an associated statement of set of statements; equivalent to "to you tell the truth".
Man is least himself when he talks in his own person. Give him a mask, and he will tell you the truth. Oscar Wilde
Let me tell you the truth. The truth is what is, and what should be is a fantasy. A terrible, terrible lie that someone gave to the people long ago. Lenny Bruce
If I could act like This was my real life, And not some cage where I've been placed, Well then, I could tell you The truth like I used to And not be afraid of sounding fake. Conor Oberst
To tell you the truth although it would put £500 in my pockets to specify my own patent rails, I cannot do so after the experience I have had. George Stephenson
Friends should always tell you the truth. But please don't. Louis C.K.
Do not bear ill will toward those who tell you the truth. Guatemalan Proverb