Kelly couldn't help raising an eyebrow at the accent switch, crinkling his nose at her tone, because it was either that or laugh, and he didn't want her getting any idea about how easy it was to get him to crack a smile (even though that was likely already out the window). He'd have to poke at her later, see if he couldn't get her to try a couple other accents. See if he couldn't find one she couldn't do, because being a brat was sometimes his only joy in life.
"And I am being perfectly nice, pup. Ain't insulted you yet, even though you stole part of my collection and insulted my bedsheets. Right generous of me, really." He could've gone for stern. Maybe. Lazily amused took less energy though, so that's what he went with, settling an elbow on his knee and propping his chin in his hand, even as he smacked her hand away with his free one. "I should be telling you to be nice, I'd think. Except we both know you'd just laugh at me and keep doing you. So, by all means," He flipped his hand with a hum, "Keep hoisting yourself up on that pedestal." His grin is all teeth, but no less genuine for it. She's not wrong after all. But where was the fun in admitting it.
"And what would you suggest I wear? I get caught in this, it looks like I'm just coming in from an errand, or fell asleep outside and ended up sneaking in again. Nothing out of the ordinary, even this late at night. Much easier to dismiss. But, if you have a better, less suspicious idea, please, enlighten me." He wasn't ignoring the second question. Not really. There were plenty of compliments he accepted. Pretty regularly too. He didn't know why her particular choice of compliments grated on his nerves, and he didn't particularly care enough to examine it. But they did, and if he had to metaphorically nip at her metaphorical hand until she got the picture, so be it.