Is it fair to be separate even if living under the same roof?
Absolutely fair.
However, I do not suggest hiding anything. The "books" should be transparent and open, and he should be able to "see everything".... just he would have ZERO access to it.
Me: 43 M: 10y S:15 ILYBINILWY 2/18/13 W moved out 2/18/13 Filed for D: 2/17/13 Got DB: 2/20/13 Got DR: 2/23/13 180 & LRT Began: 2/25/13 D Final Dec '13