(if the) truth be known

I must admit; to be honest; in actuality. Truth be known, even though I majored in English literature, I've never read anything by Hemingway! I know I said I wanted to go out to the bars tonight, but if the truth be known, I'd rather just stay home and watch a movie. A: "Truth be known, I was never that good at math when I was in school." B: "Wait, but you're an accountant now!"

if (the) ˌtruth be ˈknown/ˈtold

used to tell somebody the true facts about a situation, especially when these are not known by other people: None of the students really liked the new teacher. In fact, if the truth be told, everyone was rather afraid of him.