If she called him out on it, he'd claim he was curious. He wanted to experiment. Or, he'd blame Henry. he wanted to piss Henry off. He couldn't physically hurt Henry, for obvious reasons. He had to settle for psychologically messing with his counter part, since their brain functions were completely separate, even if their bodies were one and the same.
Penetration was impossible, given the curved angle of the tube. The best he could hope for indirect stimulation. His main focus was to bring Norah to climax by riding the tube.
"How does it feel, Norah? You like it? You like riding the cold metal? Does it excite you? I can see that it does. You should see your face. Beautiful."
He kept one hand under his cock, giving some resistance so he didn't just hang flat and hope she rode him well. He give himself lift, making sure his cock held up against the weight of her strokes. His other hand moved to the small of her back and eased down to fingert the cleft of her ass.