Every boss in the middle of the managing pyramid behaves like that... One shoud really be very cautious when talking about spare/extra time. If you admit that you have extra time, you are given by more work without raise. But if you pretend you have lots of work but work normally, you are probably the one who gets the raise. Strange. People are paid according their ability to pretend something :)
I spent my 30 year career like that. I was even admoninished for staying an hour late to ensure an important fix worked properly and not putting in for overtime because that looked as if I couldn't do my job in the time allotted and was trying to hide the fact.