I think it is difficult for us to understand why men get so turned on by the imaginary and the unattainable. Your boyfriend watching porno has no connection to how much he loves you. For some men, even if they love you and only want to be with you for the rest of their lives, they need/want to be visually stimulated by the unreal. That is key. Porno is not a reality and men know that, which is why they think it is ok for them to watch it. If it really bothers you, then he should respect that, but you most certainly do not need to take it personally and even consider that it means that he loves you less. Good luck.