He doesn't necessarily think that means Opal is amenable, though it does at least mean he's not offended. Not that it would have stopped him from flirting, but he didn't do it without a thought of offense, at least. He does maybe hedge his bets by meeting Opal's eyes a few times in some tamer songs and then straight up singing a verse of the more bawdy ones straight to him, as the night grows darker and the mood descends into such things. He's grinning as he does it, though, lets it be lighthearted, a tease more than something he intends to seriously pursue.

He does mean to pursue it, of course, but there's a bit of a delicate dance to be done here-- he doesn't want to be seen as being irritatingly forward.