Castiel had come to know the softer looks that Meg was capable of with him, but in that same token, there were others that were quite familiar as well. When she was flirting with him or otherwise trying to get a specific reaction from him, she looked much in the same way she did right now. It didn't make him uncomfortable, in fact it made him feel quite the opposite. He didn't shy away from her more confident nature, but didn't rise to meet her with a similar demeanor because he was not a creature of utmost confidence like that. He was terribly genuine, almost to a fault with Meg and while he wasn't afraid of what would come of their current interaction, he couldn't claim that was all that sure of himself, either.
"It sounds like it can be a challenging game. I assume it can be difficult, depending on the acts that the one person has chosen to act out for the other to guess?" He hadn't picked up on the innuendo that was laden throughout Meg's explanation, where she was hinting there were other activities they could be indulging in at this moment, although he was aware of their closeness. He wasn't gulping in fear, but remain steadfast and listening to her every word because he wanted to. He wanted to be there, with her, and nowhere else, really.
Her question, it was unexpected but he did look thoughtful for a moment. Then confused. "I want to spend time with you. Is that not something that I want to do?" He wondered if that was not enough and of course, the movement of her hand at his hip, it caught his attention and he looked down at it and then back at her. But he made no move to pull her hand away. Tentatively, he reached out, his hand brushing against her arm as the start of his attempting to reciprocate her contact but not knowing where to start.