Of course he'll follow. There's no question, no need for Vader to even have said the words. His motion is just as quick and confident, if not quite as militarily precise. He had, in his time in the First Order, most often found himself in some way exempted from the typical command structure, and it shows.

He doesn't know for certain whether Vader still has his chip or not, but considering how little power emanates from him, Kylo assumes he must. That's a good thing, he thinks, for now. It means that he can't sense the hint of something almost giddy underneath Kylo's serious expression.

When Vader turns, Kylo is right behind him as he expects. Which only leaves the question of how precisely to start explaining anything, now that they're in a suitable place for it. Even having the time they'd spent walking to think it over, he's still not too sure. But ultimately, he decides the only way to proceed is straightforwardly.

"I'm not simply from your future. We're related."