Eward didn't care about morals. Obviously, with the reputation he had that was not shocking, but most of the women he took to his bed were the same as him. Katherine was the complete opposite and rather than make this seem all the more wicked or wrong it felt absolutely... fine. He might even be tempted to say it was damn near bliss.
His measured strokes and continuous kisses were increasing, as was his delight at the fact he was making Katherine moan. Even if they had been fully clothed they would still be seeing each other naked - their deepest desires brought to the surface for only the other to see, giving into temptation for one another's pleasure. Eward could feel the familiar senstation in the pit of his stomach, and knew the inevitable was fast approaching - he made sure he stayed himself, wanting Katherine to reach it with him but hoping it was not too far away... if he were even giving her half the enjoyment she was to him then he knew it to be soon.