He's had a whole lot of first dates, and kissing's generally as far as things ever get on first dates, at least for him. Maybe that explains where he's gotten all of his practice. He's not thinking about being good at it, though, any more than he's consciously thinking about Ned being good at it -- although Ned is good at it, and were he thinking more rationally, he'd probably be saying something vaguely embarrassing along those lines.

"One of the better ideas I've ever heard," he agrees, nodding for Ned to keep on undoing his tie, suddenly finding that he wants nothing more than to get the tie off; he feels like it's practically choking him, but maybe that's partially the jitteriness that's still coursing through his body, the same jitteriness that makes him move his hand from the back of Ned's hair to his cheek to his shoulder, never staying in one place for too long. He has far too much energy, and he hopes it doesn't make him seem too inexperienced, too nervous.