He was breaking her heart. Which at least served to prove to her that she still had one. Somewhere. She knew she should kill him, warn Dean. Help his family fight back against Lucifer. And she could do it, he'd let her. But the thought of it, the thought of killing her husband hurt on a level she hadn't known she had before him. She sighed bitterly, watching Sam practicly throw himself against the door. He shouldn't be like this. He shouldn't be. "...It'd be easier if you didn't fight him" she said sadly. "I know, I know and a few years ago I'd have said to fight him all the way but look at you, look at us." She didn't even stop him walking to the door, he wasn't going anywhere, he was sluggish and she'd be at the door before he took two steps. They both knew it, sad as it was she had to think about these things. It wasn't fair. None of this was fair. But Dean still had to die. There was nothing else for it.
"I can't stop this anymore Sam. I tried. You know how long I tried for. But he's too strong. So it became about us. You and me and I..." She stifled a cry when he dropped the ring back on the table. He didn't mean that, he didn't. Of course he didn't. It was just another mistake. His sanity was slipping and he'd made a mistake. That was all. That was all it was. "Don't Sam..." she begged, a stray tear sliding down her cheek. "You're all I have left and I can't...without you I..."
Not the one he loved, not the Ruby he loved, she didn't understand, or more accuratly, she did understand and she didn't want to, so she did the only thing that made sense, she pushed the other her down further, far as she could so she didn't have to see any of this. Maybe she could do a better job if and when she ever got back where she was supposed to be.
No, no he was hurting himself. She rushed to his side, eyes brimming with more tears that she couldn't keep back anymore. "I couldn't do it...I tried but you said yes and it all...everything got messed up, and I tried for a long time after like you wanted. But everything in my head screamed that I needed you and he was offering me you. That was the deal. Dean he..."
How could she tell Sam that his brother was the price she was willing to pay for her selfishness. For her inability to be anything close to human without Sam.
"I love you. I do. I always will. But please...Please don't hate me and don't try to leave here. We have time now, you and me. We have time to outselves without him watching. We can talk. We can do whatever you want to do. There's food, do you want food?" Ruby needed him to remember loving her. Needed him to look at her the way he used to. She needed that to prove to herself that it was worth it. Because right now she wanted to run and hide.
It was the disappointment. She'd never been able to deal with the disappointment.