Yeah, it's not the "My god, she had sex!" that was the shocking part. You seem to be inferring something that wasn't in any way implied.
It's also about the story as much as it is about the characters, if all they wanted to show as that she wanted physical comfort or some carnal release... they could have used any other number of people, or even a wholesale created character for the purpose. Instead they used a character that they've made easily reviled and morally dubious.
That is the part I have a problem with. Not her, not even directly him, but the people who put them together for no other reason then "Hey look! What possible circumstance could have pushed these two completely disparate personalities together! It must be exciting, you should keep watching!" It was lazy writing, and sealed my already low opinion of the show.