"No!" He was quickly exclaiming, his heart twisting up a bit as he thought of how she assumed he only desired her around because she served a purpose of playing his care taker. On teaching him how to be a human and ensuring he didn't flounder under the pressure of it. "No, Meg. That's not what I think." He felt frustrated, that playing over his features because he couldn't bear her thinking that. He'd never thought that way and wouldn't start, simply because he told her he loved her and she walked away from that, out of fear. He was glad, when she didn't walk away from him this time, because he wasn't sure how he would have managed a way to get her to listen to him again in the future. He would have been forced to do quite a bit of chasing her down, he thought.
"To keep me safe? To ensure that I do not hurt myself now that I am human and prone to accidents?" Castiel's words were questioning, trying to figure out the other reasons she had for being here for him, because those were all of the reasons he didn't want her to be around for. "I truly hope that none of those are your reasons for being here. Because I want you to be here because you want to be." He was not those she'd followed in the past. He was not a cause for her to serve. He loved her, yes, but he wasn't going to keep her there against her will.