Crowley actually blinked at the vehemence in Kol's tone. Oh, he'd known that his vampire would keep the bones safe from Klaus. And everyone else. But he hadn't expected that level of tone about it. And he was actually, well he was actually moved by it. Moved that someone could feel that strongly about him, in a way that wasn't screaming hatred, because that was entirely normal for demons, obviously.
"I know." Was his simple reply. Actually genuine, no smirks, no sarcasm. "Knew I made the right choice." Kol had saved him from Lucifer, after all. After that, how could Crowley not trust him with the bones? Besides, it wasn't really that he was asking Kol to lie to Klaus, the odds of anyone turning to his vampire with a casual 'oh by the way, has Crowley given you his bones' were astronomical. But it did mean a lot that Kol had recognized the power he had been given. And Crowley trusted he wouldn't abuse it.
"Of course, it brings a whole new level to saying you can jump my bones any time," he lightened the mood and poured his own second glass of scotch before he leaned back against the chair, confident and in control of his domain, even if that was simply his room for the moment. "It never did. Really never did. It's not who I am."