不自掩饰bù zì yǎn shì

with absolute candour
❍ 他～地向学生说，以前的办法只是循例做去，外貌看来固然是个学校，实际上于学生没有多大好处。(叶圣陶《倪焕之》89) He told the boys with absolute candour that the way they had done things hitherto had been nothing more than moving in the accepted rut;although the school pased for a school so far as appearances were concerned,in actual fact the pupils were not deriving much benefit from it.