Is it an addiction? A strong sex drive and an accompanying desire to view sexually explicit activity is a very natural thing to have. Porn is easily available and its hardly surprising so many people watch a lot of porn. Having said that, there is certainly a point where too much is too much.

Is it affecting his day-to-day life and relationships? Does his desire to watch porn get him into trouble? Late for work? Turn you down for sex because he's masturbated while watching porn and has little desire for sex with you? Is he pushing views and activities that are common in porn but unrealistic in the real world upon you? Are his relationships with other people affected? Is he viewing it at inappropriate times and places?

I would suggest he feels that its unfair and disrespectful to you because he feels it takes away from the intimacy and the connection that he has with you because he's always thinking about the next porn scene to watch, or he's viewing other women as sexual objects and neglecting to have real personal connection with you - but this seems to be at odds with your experience. The other reason might be that he turns you down for sex or avoids intimacy because he'd rather use porn or uses it too much which again seems at odds with your experience.

He might be battling his own perception of what is fair and respectful. Everyone has different opinions about porn use and you certainly seems very relaxed about it. Perhaps he is someone that isnt comfortable with it and has his own guilt and hangups about his use which may actually be relatively normal?