I used to do grading after midnight as well. This is not problematic if your wife understands and trusts you. My wife understands because that is the only time it is quiet in my house with two young children. The trust factor is one that has to be earned over time, or re-earned if you did something to ruin it. A woman who has been burned in the past will need time and patience from her husband before she can sleep comfortably while he stays awake, especially if he is on the computer.