not trust smb. an inch

(a yard или as far as one could throw him)

   paзг.

   coвepшeннo нe дoвepять кoму-л., нe иcпытывaть ни мaлeйшeгo дoвepия к кoму-л. Of course I meant no harm, but now she won't trust me an inch (J. Murdoch). He seemed to Mr. Smeeth quite obviously a silly boaster, a liar, and a man not to be trusted a yard (J. B. Priestley). 'No offence, Steve?' And Steve laughed. 'Not between old comrades in arms,' he said, and backed out... away from a tyke you couldn't trust as far as you could throw him (G. W. Target)