Jim doesn’t find out Seb wants him from his pupils, or his pulse, or a hormone-laden confession. There’s not even an “as you wish”-style code phrase.
He realises it because he’s at home deleting CCTV of Sebastian’s latest fight, and he notices a pattern: man attacks Moran, Moran defends himself and immediately follows with a kill strike. Every time.
Jim goes back through every fight he can remember. It’s a consistent factor in all of them. You don’t attack Sebastian Moran and live.
Except Jim’s thrown darts at him when bored. Even razors, once. He’s only managed to nick him once or twice (Moran’s reflexes are fan-fucking-tastic) but every time Sebastian’s only sighed and either dodged, caught, or batted them aside.
Jim jumped on him in bed to wake him up last week and all he got was a low groan and “Seriously, boss? It’s fucking two-thirty.”
He’s pointed a gun at him and while Moran ducked behind a pillar there was no answering muzzle peeking out from the edge.
So when Sebastian comes home Jim decides to test it; the sniper barely closes the door before Jim has him pinned up against the wall with his face smashed into the wallpaper. And he can feel the body pressed up to his begin to tense, and a foot turns, and he knows that Moran could break this hold in less than a second.
But he doesn’t - he holds still, letting Jim capture him. So Jim hisses in his ear, “Bedroom.”
And he knows he’s calculated correctly when there’s a sharp breath and then an answering rumble of, “Fucking finally.”