[Excuse you: dozens of people would envy Yuuri the chance to dance with Sebastian (seeing as he's so dreamy and all), especially considering what an excellent dancer he is. "Nightmare" nothing.]
Very well.
[Sebastian accepts the outstretched hand, placing his other hand on Yuuri's in the correct position - with all the ease and confidence of someone who knows exactly what they're doing and also isn't particularly bothered by the "improperness" of all this.]