Makoto fully knew that dancing with a girl in the bonfire (sp?) meant they were together. And at the end he chose Sekai over Katsura for it. True, she was giving him what Katsura hadn't... but thats not the point of this post. The point is showing that he acknowledged Sekai as his girlfriend in front of the school at that moment. Selfish as it may have been after having sex with Otome... but he did.

Alas... he is an idiot. A lucky one, but an idiot.