"Don't go in, ever," he repeated dryly. "and just where do you intend that I go?" he asked, eyes a dark burnished orange suddenly, the change startling in the speed and the intensity. The cloudiness fell somewhat away, adding a luminescence to his eyes. This.... person... was going to keep him put of the bathroom, was going to dictate the parts of the room he could and could not use? Was this to be like his father all over again?

Basically, yes, he misunderstood the use of "Ever".