Out of practice. Right. Because he really should have expected that Crowley got up to that sort of thing with countless humans, lust being a cardinal sin. Still, he was surprised to find that it upset him, more than he'd ever expected it might, to have this all but confirmed by the demon. He wasn't sure why. Crowley was a demon, as much as he often let himself forget. That's what they did. "Right," he said softly, "of course...wouldn't want to get out of practice...perhaps you should go and...find someone to practice with." And clearly he was out of sorts, if he was encouraging Crowley's tempting, rather than thwarting it.
"No," he admitted, "I'm not really all right at all." He closed his eyes and took a steadying breathe, hating the way that Crowley was able to affect him without even trying. "I really should go and...get back to...I should just go."