Well I think the childlike "whiny" voice as you describe it is playful and no big deal. You might be flirting a little but that seems harmless enough. I don't think there's anything sinister or inherently bad about his smile. What doesn't sit well is that he doesn't respond when you ask him a pretty direct question. That's the part struck me as a mind game (a minor one, mind you) or being coy in a way that doesn't belong in therapy. If he doesn't want to tell you he doesn't have to, but he should give you some kind of response that makes you feel heard.