I don't think Kyo did anything wrong. He learned from his past experience with his childhood friend to be cautious when he believes that a girl might be into him, and he even confirmed his suspicion in Valentine's day when Ayame didn't even give him any chocolate (dumb move) and gave her main chocolate to the basketball guy instead.
Also, as much as he doesn't want anything to do with his childhood friend anymore (at least romantically), she's still a family friend and an important person to his siblings, so he couldn't just cut her off.
On an unrelated note, I absolutely cannot believe the guy from last chapter is still convinced that he didn't do anything wrong, and to make things worse he's even spreading false rumours again (even if unintentionally). I was happy to see that the other guys were scolding him, as I knew that the other guys who interfered with Taiki didn't seem to be as deranged as this guy. But I was still disappointed that no one told him point blank that his excuse is ass and to get f'd after he tried justifying his actions.