"I heard someone say that a man's life is a battle with his dick for self-control." Oh, yeah, we all know. ╮(￣▽￣)╭
When Hikaru said "I'd be able to hear him too...", I just couldn't help myself. He waited and waited, for whole 250 years. And maybe he just can't measure the weight of his loneliness, it's too much.
They're sinking more and more and more, and we're getting at the real question. Both, not only Shirotani, bring something from the past that's got some twist to their personality. I've realized Shirotani doesn't feel disgusted only about the outside, but at himself too. He's always concerned about getting touched or touching things that other people had put their fingers on, we all know this very well, but a lot of occasions he's concerned about Kurose getting dirtied. And dirtied by Shirotani himself. He's the dirty thing ( I bet it has something with the occasion he saw dad with that girl and, well, got off), he is too disgusting to be touched.
About Kurose, there is a lot that we don't know about him. First page of chap. 19 sent a signal, what are his eyes seeing? What is all that destruction? Few chapters ago, he was calling Shirotani cruel, and has these troubled feelings of protection and defiling. He loves Shirotani because of his mysophobia, because if Shirotani could feel disgusted about all there is outside except for Kurose himself, he would never abandon him. Was Kurose abandoned when a child? (though I feel kinda taken aback about sadists with a abandonment problems, oh well)
I am feeling a great, yet soft, melancholy right now. (▰˘◡˘▰)