You give a very clear indication of what Severus had to sacrifice to perform his duty to Dumbledore. Ironic that to protect Harry he was forced to violate him.
Of course Harry would discover the secret room. I spent all the time after the original rape waiting for that shoe to drop. How much more heart breaking for it to come after they had connected and Severus had given Harry an honest memory of love making.
I'm terribly curious what Severus was up to for those twenty years. :-) Some we know, but most. . . Nice to see that they look to be getting along.