Sob.

Kamui asking Fuuma about yaoi and getting macked on.

Hmm, good question. Kamui is one of those people Lelouch would be extremely reluctant to geass since for all intents and purposes, he meets Lelouch's classification as innocent. Lelouch does his damnest not to geass those types. He hates toying with the will of those he cares about. He might do it to protect him though. He does use geass for protection. I'm not quite sure the circumstances.