[ outside ]
[ giving a strange look before pointing to... well, a random guy in a tux. ] That's formal wear. Just like a suit but with more history. I personally think the English just wanted to look like idiots, but that's just me.
[ pointing to Yuri, wearing a suit in his usual style... ] That's casual. It might be a suit, but it definitely ain't formal.
As for the girls... well, you better ask them what's what.