A lot of the discussion on the Sansa issue is missing the point (in my opinion). As others have said, this is a show with countless acts of cruelty both physical and sexual. We have seen various forms of rape occur on screen whether it be between already existing couples, newlyweds, or strangers in the act of "conquering." No matter what the context, no one disagrees that rape is a despicable act and will cause viewer outrage.
The issue with the scene last night between Sansa and Ramsay is an issue of character development. Sansa has spent 4 seasons being the victim. In this 5th season and with the direction of her character arc, most of us believed that Sansa would be coming into her own and taking on more control in her life and in the "game of thrones." Last night's bed room scene was completely counteractive to that.
Within her character's arc, it would have made more "sense" for Sansa and Ramsay to arrive in the bedroom just exactly as they did, for Sansa to initially show hesitation, but to overcome her fear by applying the lessons that she's learned from all her past tragedies. I think some viewers/readers expected Sansa to at least fake being into it after getting past that initial hesitation in order to bait Ramsay into placing his trust in her, which she would ultimately use to betray and overthrow the Boltons when justice finally comes.
Instead, Sansa once again played the victim in that scene. And the way it played out, she was the victim. There is no questioning that. The point is, it shouldn't have been written like that, with her as the victim, again.
It's also worth noting that even though this occurred, Sansa may still trick the Boltons and be an instrument in their downfall. I think most of us just expected it to ultimate begin with that scene. The show may still take that route. I think a lot of us were just expecting the show to really put it into motion with that scene and they didn't.