Itachi didn't leave his stash at Shisuis; Shisui stocked up for both of them. Mostly because he knew Itachi wouldn't bother eating otherwise, especially when he crept into Shisui's place when no one was around to escape staying at home.

"Hm. Who really was the third wheel, Sasuke. You or me?" That's just him saying that Sasuke wasn't the third wheel ever, and that Itachi never considered him t be one at all. Just that Itachi and Shisui were more closer in mental age at the time. "And I'd trust you'd respect his wishes to stay away from home when he needed the rest and not call him home at a time like that."

But ah. Back to 'the topic'. Shisui dropped a tea bag into Sasuke's cup before pouring hot water into it.

"Okay. So... You're telling me this because?"