He did bring up that Tadashi should contact him when he had an idea. And it's relatively easy to change phones; they're called 'burners' for a reason. He has no plans to use this one for overly long; it's already his second, and so long as he wipes the information thoroughly, there shouldn't be much of an issue of things being...complicated.

And he did mention it's not secure.

He does have to glance down through the settings to remember the numbers, though, which he rattles off quickly enough before adding, "that may change. But I'll see what I can do to update you if it does."

A pause.

"I won't always be able to respond. You...understand this."

Possibly he doesn't, but if they're going to have this...arrangement...then this is the time to set the ground rules.