Shirogane doesn't even need to turn to look to know that it's Aria-shachou. He's long decided that there isn't a point to denying that cat anything (within reason, of course). But he's fairly certain that he can probably climb up on his own. Besides, Shirogane is comfortable in his current position, so he doesn't offer Aria-shachou any help.

Instead, he wraps an arm around Akari's waist, waiting for the moment when Aria-shachou will inevitably get on the bed and insist on snuggling with them.