Английский словарь американских идиом - keep one at a distance

or keep one at arm's length {v. phr.} To avoid (someone's) company; not become too friendly toward. * /Mr. Smith is kind to the workers in his store but after work he keeps them at a distance./ * /Betty likes Bill and is trying to be friendly, but he keeps her at arm's length./ Compare: KEEP ONE'S DISTANCE, HOLD OFF(1a).