I like her to watch

To get myself really ready to take care of some business I start out by having my girlfriend sit on the bed naked and watch while I jerk off for awhile. Man this gets me hot! No I don't blow my cookies. It just turns my cock into a fucking battering ram. Which, of course, turns her on so she's always glad to do it. It's the having her watch that gets me so heated. Is this normal?