It's something of a clue, yes, but then it could just have been a while for her, or she's just smaller than average. And it's not like he'd taken the time to do any actual prep work. Not that she'd asked for it, or that she seems to be missing it, but he does wonder. Even at a time like this, it's not like he can just turn his mind off. It's always picking up context clues, looking at a situation, analyzing...truthfully, there are a lot of times he'd rather be able to turn it off. But then, if he did, he wouldn't be able to use that for her benefit, would he? And that would be a shame.

"I won't," he murmurs against her lips, fingers tight on her thighs, pushing up slowly, slowly, until he's fully seated inside of her, almost breathless for the feeling of it. "You feel amazing, Mikan-chan, it's perfect--" He'll pause for just a moment, long enough for her to start to get used to the feeling, before he shifts just a little. Enough to start making room, enough to add a little friction. Enough that she should definitely be able to respond, to do some moving of her own, if she wants.